Linux Kernel Development: How Fast it is Going, Who is Doing It, What They are Doing, and Who is Sponsoring It - Corbet, Jonathan; Greg Kroah-Hartman; Amanda McPherson (The Linux Foundation, 2012)
The kernel which forms the core of the Linux system is the result of one of the largest cooperative software projects ever attempted. Regular 2-3 month releases deliver stable updates to Linux users, each with signi cant new features, added device support, and improved performance. The rate of change in the kernel is high and increasing, with between 8,000 and 12,000 patches going into each recent kernel release. These releases each contain the work of over 1,000 developers representing nearly 200 corporations. Since 2005, over 7,800 individual developers from almost 800 different companies have contributed to the kernel. The Linux kernel, thus, has become a common resource developed on a massive scale by companies which are erce competitors in other areas. This is the fourth update of this document, which has been published roughly annually since 2008. It covers development through the 3.2 release, with an emphasis on the releases (2.6.36 to 3.2) made since the last update. It has been a busy period, with seven kernel releases created, many signi cant changes made, and continual growth of the kernel developer and user community.
Keywords: corporate; corporations; developers; linux kernel; metrics

Long-Term Sustainability of Open Source Software Communities beyond a Fork: A Case Study of LibreOffice - Gamalielsson, Jonas; Lundell, Björn (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Many organisations have requirements for long-term sustainable software systems and associated communities. In this paper we consider long-term sustainability of Open Source software communities in Open Source projects involving a fork. There is currently a lack of studies in the literature that address how specific Open Source software communities are affected by a fork. We report from a case study aiming to investigate the developer community around the LibreOffice project, which is a fork from the OpenOffice.org project. The results strongly suggest a long-term sustainable community and that there are no signs of stagnation in the project 15 months after the fork. Our analysis provides details on the LibreOffice developer community and how it has evolved from the OpenOffice.org community with respect to project activity, long-term involvement of committers, and organisational influence over time. The findings from our analysis of the LibreOffice project make an important contribution towards a deeper understanding of challenges regarding long-term sustainability of Open Source software communities.

A Model of Open Source Developer Foundations - Dirk Riehle; Sebastian Berschneider (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Many community open source projects are of high economic relevance. As these projects mature, their leaders face a choice of continuing the project as is, making the project join an existing foundation, or creating their own foundation for the project. This article presents a model of open source developer foundations that project leaders can use to compare existing foundations with their needs or to design their own. The model is based on a three- iteration qualitative study involving interviews and supplementary materials review. To demonstrate its usefulness, we apply the model to nine foundations and present their organizational choices in a comparative table format.

Modification and developer metrics at the function level: Metrics for the study of the evolution of a software project - Gregorio Robles; Herraiz, Israel; Daniel M. German; Izquierdo-Cortazar, Daniel (2012 3rd International Workshop on Emerging Trends in Software Metrics (WETSoM), 2012)
Software evolution, and particularly its growth, has been mainly studied at the file (also sometimes referred as module) level. In this paper we propose to move from the physical towards a level that includes semantic information by using functions or methods for measuring the evolution of a software system. We point out that use of functions-based metrics has many advantages over the use of files or lines of code. We demonstrate our approach with an empirical study of two Free/Open Source projects: a community-driven project, Apache, and a company-led project, Novell Evolution. We discovered that most functions never change; when they do their number of modifications is correlated with their size, and that very few authors who modify each; finally we show that the departure of a developer from a software project slows the evolution of the functions that she authored.

Network-Based Analysis of the Structure and Evolution of an Open Source Software Product - Le, Qize; Panchal, Jitesh H. (45th Hawai'i International Conference on System Sciences, 2012)
In this paper, an analysis of product structures in open source software (OSS) at both product level and module level is presented. At the product level, the product structures are modeled as complex networks, and the evolutionary characteristics of product structures are analyzed by using network analysis metrics. At the module level, linking mechanisms, which describe how a module is attached with other modules, are proposed. The linking mechanisms are modeled as probability functions dependent on the degrees of linking modules. A case study from an open source software project, Drupal, is presented. The evolutionary trends of Drupal product structures are analyzed and discussed. Finally, a model is presented to illustrate the effects of linking mechanisms at the module level on the product structures at the system level. The results indicate that the model built using the proposed linking mechanisms generates networks whose evolutionary characteristics are close to that of the original network.
Keywords: drupal; source code

A Novel Application of Open Source Technologies to Measure Agile Software Development Process - Corral, Luis; Janes, Andrea; Remencius, Tadas; Strumpflohner, Juri; Vlasenko, Jelena (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
In the last 10 years Open Source products have been widely used in industry. New methodologies and best practices to develop Open Source software appeared. In this work, we present an application that runs on Android-based mobile phones and collects proximity data with other devices via Bluetooth. The application gives new insights into measuring proximity inside a team of software developers. Data collection process is automatic so that the team members are not distracted from their daily activities. The collected data represent time frames when developers work alone at their machines and when they do Pair Programming with their colleagues.

Open Source Migration in Greek Public Sector: A Feasibility Study - Mavridis, Androklis; Fotakidis, Dimitrios; Ioannis Stamelos (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Open Source software has been recently recognized by governments as a viable and cost effective solution. However, transition to open source is not a plug-and-play process but one that requires deep knowledge of open source dynamics and of organization's operations, budgetary constraints, capacities, ethics and political agenda. As with any IT transition, there are uncertainties and risks that need to be handled in order to maximize the gains for the organization and for the society through the provided services. In this paper we present a feasibility study conducted in 15 Greek public sector organizations with the aim to discover the value this transition brings to a typical public sector organization.

Open Source, Open Innovation and Intellectual Property Rights – A Lightning Talk - Kilamo, Terhi; Hammouda, Imed; Kairamo, Ville; Rasanen, Petri; Saarinen, Jukka P. (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Open innovation projects are fast paced aiming at producing a quick proof of concept of an innovative software product. This need for speedy results makes the use of open source components as a basis for the work appealing. Open source brings with it an inherent risk of license conflicts that may become an issue when aiming to develop an innovative demo into an actual product. In this study, the first results of investigating the knowledge the participants of innovation projects have on intellectual property are presented. The effect this may have on the project results is also discussed.

Open Source Prediction Methods: A Systematic Literature Review - Syeed, M.M. Mahbubul; Kilamo, Terhi; Hammouda, Imed; Systä, Tarja (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
For the adoption of Open Source Software (OSS) components, knowledge of the project development and associated risks with their use is needed. That, in turn, calls for reliable prediction models to support preventive maintenance and building quality software. In this paper, we perform a systematic literature review on the state-of-the- art on predicting OSS projects considering both code and community dimension. We also distill future direction for research in this field.
Keywords: Prediction Success; Systematic literature review

Open-Source Technologies Realizing Social Networks: A Multiple Descriptive Case-Study - Teixeira, Jose (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
This article aims at describing the role of the open-source software phenomenon within high-tech corporations providing social networks and applications. By taking a multiple case study approach, We address what are the open-source software technological components embedded by leading social networking players, and a rich description on how those players collaborate with the open-source community. Our findings, based on a population of three commercial providers of social networks a suggest that open-source plays an important role on the technological development of their social networking platforms. An open-source technological stack for realizing social networks is proposed and several managerial issues dealing with collaboration with open-source communities are explored.
Keywords: entrepreneurship; facebook; netlog; social networks; spotify

OSS Adoption in South Africa: Applying the TOE Model to a Case Study - Van Belle, Jean-Paul; Reed, Mark (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
This paper presents a case study on the factors that influence the initial adoption of Open Source Software (OSS) in a large South African organization when implementing an OSS PBX platform. The theoretical foundation for this research draws on a number of academic frameworks and models, thus not only providing a practical illustration but also validating their usefulness in guiding OSS adoption.

OSS in 2012: A Long-Term Sustainable Alternative for Corporate IT - Durand, Didier; Vuattoux, Jean-Luc; Ditscheid, Pierre-Jean (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
The current internet leaders (Google, Facebook, etc.) all have OSS in their DNA. Traditional corporations still rely mostly on proprietary software for their mission-critical IT systems. But, situation is changing: as tip of the iceberg, major stock exchanges of the world have announced successful migrations to OSS. Many traditional corporations can now follow the OSS path because this market has clearly matured in many relevant aspects for them. In addition, solutions are here to achieve quick, efficient and secure mutations to OSS which must be undoubtedly considered by CIOs as the technological state of the art for 2012.

OSS Integration Issues and Community Support: An Integrator Perspective - Ayala, Claudia; Cruzes, Daniela S.; Nguyen, Anh Duc; Conradi, Reidar; Franch, Xavier; Höst, Martin; Ali Babar, Muhammad (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
The reuse and integration of Open Source Software (OSS) components provided by OSS communities is becoming an economical and strategic need for today’s organizations. The integration of OSS components provides many benefits, but also risks and challenges. One of the most important risks is the lack of effective and timely OSS community support for dealing with possible integration problems. For gaining an understanding of the common problems that organizations face when integrating OSS components, and the role played by OSS communities, we performed an exploratory study on 25 OSS integration projects from different European organizations. The results show that the main way of reducing integration problems was the use of OSS components from well-established communities; therefore very few integration problems were identified. In most of the cases these problems were successfully solved with the support from the OSS community and/or colleagues. In addition, contrary to the common belief that understanding code from someone else is a hard and undesirable task, some integrators consider OSS code even more understandable than their own code.

OSSLI: Architecture Level Management of Open Source Software Legality Concerns - Lokhman, Alexander; Luoto, Antti; Abdul-Rahman, Salum; Hammouda, Imed (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
This paper presents a tool that addresses the legality concerns of open source at the level of software architecture, early in the development activity. The tool demonstrates the significance of licensing concerns at the architectural level by extending existing modeling tools with support for open source licensing issues.

Perspectives on Code Forking and Sustainability in Open Source Software - Nyman, Linus; Mikkonen, Tommi; Juho Lindman; Fougère, Martin (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
The ability to create high-quality software artifacts that are usable over time is one of the essential requirements of the software business. In such a setting, open source software offers excellent opportunities for sustainability. In particular, safeguarding mechanisms against planned obsolescence by any single actor are built into the definition of open source. The most powerful of these mechanisms is the ability to fork the project. In this paper we argue that the possibility to fork serves as the invisible hand of sustainability that ensures that code remains open and that the code that best serves the community lives on. Furthermore, the mere option to fork provides a mechanism for safeguarding against despotic decisions by the project lead, who is thus guided in their actions to consider the best interest of the community.

A Qualitative Method for Mining Open Source Software Repositories - Noll, John; Seichter, Dominik; Beecham, Sarah (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
The volume of data archived in open source software project repositories makes automated, quantitative techniques attractive for extracting and analyzing information from these archives. However, many kinds of archival data include blocks of natural language text that are difficult to analyze automatically. This paper introduces a qualitative analysis method that is transparent and repeatable, leads to objective findings when dealing with qualitative data, and is efficient enough to be applied to large archives. The method was applied in a case study of developer and user forum discussions of an open source electronic medical record project. The study demonstrates that the qualitative repository mining method can be employed to derive useful results quickly yet accurately. These results would not be possible using a strictly automated approach.
Keywords: content analysis; Electronic Medical Record; Qualitative Research

Similarities, challenges and opportunities of Wikipedia content and open source projects - Capiluppi, Andrea (Journal of Software: Evolution and Process, 2012)
Several years of research and evidence have demonstrated that open source software portals often contain a large amount of software projects that simply do not evolve, developed by relatively small communities, struggling to attract a sustained number of contributors. These portals have started to increasingly act as a storage for abandoned projects, and researchers and practitioners should try and point out how to take advantage of such content. Similarly, other online content portals (like Wikipedia) could be harvested for valuable content. In this paper we argue that, even with differences in the requested expertise, many projects reliant on content and contributions by users undergo a similar evolution, and follow similar patterns: when a project fails to attract contributors, it appears to be not evolving, or abandoned. Far from a negative finding, even those projects could provide valuable content that should be harvested and identified based on common characteristics: by using the attributes of ‘usefulness’ and ‘modularity’ we isolate valuable content in both Wikipedia pages and open source software projects.
Keywords: flossmole

Social coding in GitHub - Laura Dabbish; Colleen Stuart; Jason Tsay; Herbsleb, Jim (Proceedings of the ACM 2012 conference on Computer Supported Cooperative Work - CSCW '12, 2012)
Social applications on the web let users track and follow the activities of a large number of others regardless of location or affiliation. There is a potential for this transparency to radically improve collaboration and learning in complex knowledge-based activities. Based on a series of in-depth interviews with central and peripheral GitHub users, we examined the value of transparency for large-scale distributed collaborations and communities of practice. We find that people make a surprisingly rich set of social inferences from the networked activity information in GitHub, such as inferring someone else's technical goals and vision when they edit code, or guessing which of several similar projects has the best chance of thriving in the long term. Users combine these inferences into effective strategies for coordinating work, advancing technical skills and managing their reputation.
Keywords: github

Software Bertillonage - Davies, Julius; German, Daniel; Michael Godfrey; Hindle, Abram (Empirical Software Engineering, 2012)
Deployed software systems are typically composed of many pieces, not all of which may have been created by the main development team. Often, the provenance of included components—such as external libraries or cloned source code—is not clearly stated, and this uncertainty can introduce technical and ethical concerns that make it difficult for system owners and other stakeholders to manage their software assets. In this work, we motivate the need for the recovery of the provenance of software entities by a broad set of techniques that could include signature matching, source code fact extraction, software clone detection, call flow graph matching, string matching, historical analyses, and other techniques. We liken our provenance goals to that of Bertillonage, a simple and approximate forensic analysis technique based on bio-metrics that was developed in 19th century France before the advent of fingerprints. As an example, we have developed a fast, simple, and approximate technique called anchored signature matching for identifying the source origin of binary libraries within a given Java application. This technique involves a type of structured signature matching performed against a database of candidates drawn from the Maven2 repository, a 275 GB collection of open source Java libraries. To show the approach is both valid and effective, we conducted an empirical study on 945 jars from the Debian GNU/Linux distribution, as well as an industrial case study on 81 jars from an e-commerce application.

Software Libre y abierto: comunidades y redes de producción digital de bienes comunes - Tania E. Turner Sen (Universidad Nacional Autónoma de México, 2012)
This thesis is about a collective form of production that have expanded and strengthen in the global high technology market. It is about FLOSS production. The study takes on account that technnologies are not neutral, they emerge as strategies and mechanisms of politics and economic interests. Although, FLOSS production is inserted in the capitalist context, the collective work of the communities and networks that produce it is based on ideas about freedom and solidarity. The types of rules and organization of labour inside of this communities have develop a kind of product that it is well categorized as part of the new commons. The conclusions at the end of this work pretend to offer a clear approach to the FLOSS production networks dynamics inside the virtual infrastructure. Specifically, it offers an approach of the interaction and forms of cooperation, as well of the individual and collective schemas that motivates the cooperation action of the individuals.
Keywords: bienes comunes; commons; comunidades virtuales; FLOSS; flossmole; hackers; redes virtuales; repositories; repositorios; Software libre y abierto; virtual communities; virtual networks

Software licenses, coverage, and subsumption - Alspaugh, Thomas A.; Walt Scacchi; Kawai, Rihoko (2012 Fifth International Workshop on Requirements Engineering and Law (RELAW)2012 Fifth IEEE International Workshop on Requirements Engineering and Law (RELAW), 2012)
Software licensing issues for a system design, instantiation, or configuration are often complex and difficult to evaluate, and mistakes can be costly. Automated assistance requires a formal representation of the significant features of the software licenses involved. We present results from an analysis directed toward a formal representation capable of covering an entire license. The key to such a representation is to identify the license's actions, and relate them to the actions for exclusive rights defined in law and to the actions defined in other licenses. Parameterizing each action by the object(s) acted on, the instrumental entities through which the action is performed, and similar contextual variables enables a subsumption relation among the actions. The resulting formalism is lightweight, flexible enough to support the scope of legal interpretations, and extensible to a wide range of software licenses. We discuss the application of our approach to the Lesser General Public License (LGPL) version 2.1.

Step-by-Step Strategies and Case Studies for Embedded Software Companies to Adapt to the FOSS Ecosystem - Kim, Suhyun; Yoo, Jaehyun; Lee, Myunghwa (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Due to the continuous expansion of the FOSS ecosystem and the introduction of high-quality FOSS, FOSS is increasingly used in consumer electronics (CE) such as smartphones, televisions, and cameras. As a result, manufacturers of CE products have developed a close relationship with the FOSS ecosystem. For CE product manufacturers, efficient adaptation to the FOSS ecosystem has become an essential component in their business operations. This paper will divide the activities of CE product manufacturers within the FOSS ecosystem into the following four levels: identification, adoption, compliance, and contribution. It will examine the main activities and obstacles that arise in each level. The paper will also present instances where companies have succeeded in overcoming these obstacles.
Keywords: embedded software; FOSS ecosystem

A Study on OSS Marketing and Communication Strategies - del Bianco, Vieri; Lavazza, Luigi; Lenarduzzi, Valentina; Morasca, Sandro; Taibi, Davide; Tosi, Davide (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
The goal of every open source project is to gain as many satisfied users as possible. To this end, open source software producers should focus on both product development and communication. Currently, most open source projects are mainly concerned with developing code using the most appealing technologies and introducing fancy features. On the contrary, open source software producers seem to lack good communication strategies. In this paper we describe the communication strategies adopted by three successful companies that are active in open source software development. The goal of the paper is to provide some hints that could help other open source software producers identify communication strategies that are effective in promoting their products on the market.

Studying the impact of social interactions on software quality - Bettenburg, Nicolas; Hassan, Ahmed E. (Empirical Software Engineering, 2012)
Correcting software defects accounts for a significant amount of resources in a software project. To make best use of testing efforts, researchers have studied statistical models to predict in which parts of a software system future defects are likely to occur. By studying the mathematical relations between predictor variables used in these models, researchers can form an increased understanding of the important connections between development activities and software quality. Predictor variables used in past top-performing models are largely based on source code-oriented metrics, such as lines of code or number of changes. However, source code is the end product of numerous interlaced and collaborative activities carried out by developers. Traces of such activities can be found in the various repositories used to manage development efforts. In this paper, we develop statistical models to study the impact of social interactions in a software project on software quality. These models use predictor variables based on social information mined from the issue tracking and version control repositories of two large open-source software projects. The results of our case studies demonstrate the impact of metrics from four different dimensions of social interaction on post-release defects. Our findings show that statistical models based on social information have a similar degree of explanatory power as traditional models. Furthermore, our results demonstrate that social information does not substitute, but rather augments traditional source code-based metrics used in defect prediction models.
Keywords: bug tracker; eclipse; Firefox; Human Factors; measurement; metrics; software evolution; Software quality assurance

Time-Based Release Management in Free and Open Source (FOSS) Projects - Martin Michlmayr; Fitzgerald, Brian (International Journal of Open Source Software and Processes, 2012)
As the Free and Open Source (FOSS) concept has matured, its commercial significance has also increased, and issues such as quality and sustainability have moved to the fore. In this study, we focus on time-based release management in large volunteer FOSS projects, and reveal how it addresses quality and sustainability issues. We discuss the differences between release management in the traditional software context and contrast it with FOSS settings. Based on detailed case studies of a number of prominent FOSS projects, we describe the move to time-based release management and identify the factors and criteria necessary for a successful transition. We also consider the implications for software development more generally in the current dynamic Internet-enabled environment.

Two Evolution Indicators for FOSS Projects - Petrinja, Etiel; Succi, Giancarlo (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
In this paper we introduce two project evolution indicators. One is showing an increase of downloads of the project and therefore a growing interest of users in the results of the project. The second indica- tor is predicting the future evolution of the project with the submission of new revisions to the concurrent versioning system. Both indicators can provide evidence of the sustainability of a software project. We used the General Linear Model method to statistically formulate the two linear equations that can be used to predict the two indicators. The predicting equations were build by using two stratified data samples one of 760 projects and the second of 880 projects extracted from the SourceForge repository. The six metrics included into the final version of the two models were extracted from a set of thirty project and product metrics as: the number of downloads, the number of developers, etc. We have validated the discriminant and the concurrent validity of the two models by using different statistical tests as the goodness-of-fit and we have used the two models to predict the indicators on two hold-out validation samples. The model predicting the increment of downloads was correct in 75 percent of the cases, the model predicting the submission of new revisions was correct in 93 percent of the cases.
Keywords: metrics; sourceforge

Two Modes of Product Development: Head-Oriented vs. Release-Oriented - Hatta, Masayuki (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
In this paper, the concept of two different modes for product development process is proposed. One is “release-oriented” product development, which is a fairly common way to develop various products up to now. The other is “head-oriented” product development, which is recently observed especially in the field of software/content development. The distinguishing difference and possible merits and demerits of two modes are scrutinized.

Using Code Search to Link Code Fragments in Discussions and Source Code - Bettenburg, Nicolas; Stephen W. Thomas; Hassan, Ahmed E. (CSMR '12: Proceedings of the 16th European Conference on Software Maintenance and Reengineering, 2012)
When discussing software, practitioners often reference parts of the project’s source code. Such references have different motivations, such as mentoring and guiding less experienced developers, pointing out code that needs changes, or proposing possible strategies for the implementation of future changes. The fact that particular parts of a source code are being discussed makes these parts of the software special. Knowing which code is being talked about the most can not only help practitioners to guide important software engineering and maintenance activities, but also act as a high-level documentation of development activities for managers. In this paper, we use clone-detection as specific instance of a code search based approach for establishing links between code fragments that are discussed by developers and the actual source code of a project. Through a case study on the Eclipse project we explore the traceability links established through this approach, both quantitatively and qualitatively, and compare fuzzy code search based traceability linking to classical approaches, in particular change log analysis and information retrieval. We demonstrate a sample application of code search based traceability links by visualizing those parts of the project that are most discussed in issue reports with a Treemap visualization. The results of our case study show that the traceability links established through fuzzy code search-based traceability linking are conceptually different than classical approaches based on change log analysis or information retrieval.

Using Multiple Case Studies to Analyse Open Source Software Business Sustainability in Sub-Saharan Africa - Sowe, Sulayman K.; McNaughton, Maurice (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Amidst the debate about what sort of technology is appropriate for achieving sustainable development, Free and Open Source Software (FOSS) offers some solutions to today's technology problems for many developing countries. However, there is a paucity of empirical evidence to help us understand the potentials FOSS technologies have for small businesses in Sub-Saharan Africa. This research utilizes nine case studies data from seven African countries to find out how entrepreneurs are leveraging FOSS to help them create sustainable business based on openness. The findings show increasing awareness of the business potential of FOSS, and a business model incorporating both FOSS and proprietary software is needed to run a sustainable IT business in these countries. However, the lack of skilled FOSS developer base, the absence of appropriate policies, and poor payment habits by clients are just some of the factors affecting businesses. Other problems encountered, possible solutions to those problems and lessons to be learnt from each case study are also discussed. The research offers entrepreneurs, ICT practitioners, and policy makers the platform to understand the Why and How FOSS technologies are impacting the traditional way of doing business in Sub-Saharan Africa.

Using Pig as a data preparation language for large-scale mining software repositories studies: An experience report - Weiyi Shang; Adams, Bram; Hassan, Ahmed E. (Journal of Systems and Software, 2012)
The Mining Software Repositories (MSR) field analyzes software repository data to uncover knowledge and assist development of ever growing, complex systems. However, existing approaches and platforms for MSR analysis face many challenges when performing large-scale MSR studies. Such approaches and platforms rarely scale easily out of the box. Instead, they often require custom scaling tricks and designs that are costly to maintain and that are not reusable for other types of analysis. We believe that the web community has faced many of these software engineering scaling challenges before, as web analyses have to cope with the enormous growth of web data. In this paper, we report on our experience in using a web-scale platform (i.e., Pig) as a data preparation language to aid large-scale MSR studies. Through three case studies, we carefully validate the use of this web platform to prepare (i.e., Extract, Transform, and Load, ETL) data for further analysis. Despite several limitations, we still encourage MSR researchers to leverage Pig in their large-scale studies because of Pig's scalability and flexibility. Our experience report will help other researchers who want to scale their analyses.
Keywords: flossmole cited

Who? What? Where? Examining Distributed Development in Two Large Open Source Projects - Christian Bird; Nachiappan Nagappan (Proceedings of the Working Conference on Mining Software Repositories, 2012)
To date, a large body of knowledge has been built up around understanding open source software development. However, there is limited research on examining levels of geographic and organizational distribution within open source software projects, despite many studies examining these same aspects in commercial contexts. We set out to fill this gap in OSS knowledge by manually collecting data for two large, mature, successful projects in an effort to assess how distributed both geographically and organizationally. Both Firefox and Eclipse have been the subject of many studies and are ubiquitous in the areas of software development and internet usage respectively. Further, both receive substantial development contributions from many companies. As such, both are worthy of study in order to understand the development processes that they use, how distributed the projects are, and what, if any, relationship distribution has with quality. To this end, we identified the top contributors that made 95% of the changes over multiple major releases of Firefox and Eclipse and determined their geographic locations and organizational affiliations. We found that Firefox is very geographically distributed with over a third of its components receiving major contributions from developers on different continents, and that components that are highly distributed have no more defects than those that are not. In contrast, Eclipse is directed and developed largely by one company; with IBM making 96% of the total commits (49% coming from one lab in Ottawa, Canada). We further examined the distribution in each project’s constituent subsystems and report the relationship of pre- and post-release defects with geographic and organizational factors.
Keywords: eclipse; Firefox

Who Will Remain? An Evaluation of Actual Person-Job and Person-Team Fit to Predict Developer Retention in FLOSS Projects - Schilling, A.; Laumer, S.; Weitzel, T. (45th Hawai'i International Conference on System Sciences, 2012)
Many businesses and private households rely on Free Libre Open Source Software (FLOSS). Due to a lack of sustained contributors, however, most FLOSS projects do not survive. The early identification of developers who are likely to remain is thus an eminent challenge for the management of FLOSS initiatives. Previous research has shown that individuals' subjective assessment is often inaccurate emphasizing the need to objectively evaluate retention behavior. Consistent with the concepts Person-Job (P-J) and Person-Team (P-T) fit from the traditional recruitment literature, we derive objective measures to predict developer retention in FLOSS projects. In an analysis of the contribution behavior of former Google Summer of Code (GSoC) students we reveal that the level of development experience and conversational knowledge is strongly associated with retention. Surprisingly, our analysis reveals that students with abilities that are underrepresented in the project and students with a higher academic education do not remain considerably longer.
Keywords: email; email archives; google summer of code; kde; mailing list; students

Adopting Free/Libre/Open Source Software Practices, Techniques and Methods for Industrial Use - Torkar, Richard; Minoves, Pau; Garrigós, Janina (Journal of the Association for Information Systems, 2011)
Today’s software companies face the challenges of highly distributed development projects and constantly changing requirements. This paper proposes the adoption of relevant Free/Libre/Open Source Software (FLOSS) practices in order to improve software development projects in industry. Many FLOSS projects have proven to be very successful, producing high quality products with steady and frequent releases. This study aims to identify FLOSS practices that can be adapted for the corporate environment. To achieve this goal, a framework to compare FLOSS and industrial development methodologies was created. Three successful FLOSS projects were selected as study targets (the Linux Kernel, the FreeBSD operating system, and the JBoss application server), as well as two projects from Ericsson, a large telecommunications company. Based on an analysis of these projects, FLOSS best practices were tailored to fit industrial development environments. The final results consisted of a set of key adoption opportunities that aimed to improve software quality and overall development productivity by importing best practices from the FLOSS environment. The adoption opportunities were then validated at three large corporations.
Keywords: freebsd; jboss; linux; linux kernel

Adoption of OSS Development Practices by the Software Industry: A Survey - Petrinja, Etiel; Sillitti, Alberto; Succi, Giancarlo (Open Source Systems: Grounding Research (OSS 2011), 2011)
The paper presents a survey of aspects related to the adoption of Open Source Software by the software industry. The aim of this study was to collect data related to practices and elements in the development process of companies that influence the trust in the quality of the product by potential adopters. The work is part of the research done inside the QualiPSo project and was carried out using a qualitative study based on a structured questionnaire focused on perceptions of experts and development practices used by companies involved in the Open Source Software industry. The results of the survey confirm intuitive concerns related to the adoption of Open Source Software as: the selection of the license, the quality issues addressed, and the development process tasks inside Open Source Software projects. The study uncovered specific aspects related to trust and trustworthiness of the Open Source Software development process that we did not find in previous studies as: the standards implemented by the OSS project, the project's roadmap is respected, and the communication channels that are available.
Keywords: qualipso; Survey

An Analysis of Author Contribution Patterns in Eclipse Foundation Project Source Code - Taylor, Quinn C.; Krein, Jonathan L.; MacLean, Alexander C.; Knutson, Charles D. (Open Source Systems: Grounding Research (OSS 2011), 2011)
Collaborative development is a key tenet of open source software, but if not properly understood and managed, it can become a liability. We examine author contribution data for the newest revision of 251,633 Java source files in 592 Eclipse projects. We use this observational data to analyze collaboration patterns within files, and to explore relationships between file size, author count, and code authorship. We calculate author entropy to characterize the contributions of multiple authors to a given file, with an eye toward understanding the degree of collaboration and the most common interaction patterns.
Keywords: COLLABORATION; contribution; eclipse; entropy; java

Apples vs. oranges? - Davies, Julius; Daniel M. German (Proceedings of the 8th working conference on Mining software repositories - MSR '11, 2011)
We attempt to compare the source code of two Java IDE systems: Netbeans and Eclipse. The result of this experiment shows that many factors, if ignored, could risk a bias in the results, and we posit various observations that should be taken into consideration to minimize such risk.
Keywords: eclipse; netbeans; source code

Applying Open Source Practices and Principles in Open Innovation: The Case of the Demola Platform - Kilamo, Terhi; Hammouda, Imed; Kairamo, Ville; Rasanen, Petri (Open Source Systems: Grounding Research (OSS 2011), 2011)
In numerous fields, businesses have to rely on rapid development and release cycles. Variant new ideas and concepts can emerge through open innovation as the participants are not limited to the company scope. This makes open innovation an increasingly appealing option for the industry. One such open innovation platform, Demola, allows university students to work on real life industrial cases of their own interest. We have identified similarities with its way of operation to open source software development and find that it offers a viable motivational, organizational and collaborative solution to open innovation.

Are Developers Fixing Their Own Bugs? - Izquierdo-Cortazar, Daniel; Capiluppi, Andrea; Jesus M. Gonzalez-Barahona (International Journal of Open Source Software and Processes, 2011)
The process of fixing software bugs plays a key role in the maintenance activities of a software project. Ideally, code ownership and responsibility should be enforced among developers working on the same artifacts, so that those introducing buggy code could also contribute to its fix. However, especially in FLOSS projects, this mechanism is not clearly understood: in particular, it is not known whether those contributors fixing a bug are the same introducing and seeding it in the first place. This paper analyzes the comm-central FLOSS project, which hosts part of the Thunderbird, SeaMonkey, Lightning extensions and Sunbird projects from the Mozilla community. The analysis is focused at the level of lines of code and it uses the information stored in the source code management system. The results of this study show that in 80% of the cases, the bug-fixing activity involves source code modified by at most two developers. It also emerges that the developers fixing the bug are only responsible for 3.5% of the previous modifications to the lines affected; this implies that the other developers making changes to those lines could have made that fix. In most of the cases the bug fixing process in comm-central is not carried out by the same developers than those who seeded the buggy code.
Keywords: bug fixing; developers; loc; scm

Aspects of an Open Source Software Sustainable Life Cycle - Arantes, Flavia Linhalis; Freire, Fernanda Maria Pereira (Open Source Systems: Grounding Research (OSS 2011), 2011)
In this paper we present a literature overview about OSS sustainability, considering not only financial resources, but also community growth, source code and tools management. Based on these aspects, we define an OSS life cycle that may contribute to OSS projects sustainability.
Keywords: Financial Resources; OSS Communities; OSS Sustainability; software maintenance

Building Knowledge in Open Source Software Research in Six Years of Conferences - Mulazzini, Fabio; Rossi, Bruno; Russo, Barbara; Steff, Maximilian (Open Source Systems: Grounding Research (OSS 2011), 2011)
Since its origins, the diffusion of the OSS phenomenon and the information about it has been entrusted to the Internet and its virtual communities of developers. This public mass of data has attracted the interest of researchers and practitioners aiming at formalizing it into a body of knowledge. To this aim, in 2005, a new series of conferences on OSS started to collect and convey OSS knowledge to the research and industrial community. Our work mines articles of the OSS conference series to understand the process of knowledge grounding and the community surrounding it. As such, we propose a semi-automated approach for a systematic mapping study on these articles. We automatically build a map of cross-citations among all the papers of the conferences and then we manually inspect the resulting clusters to identify knowledge building blocks and their mutual relationships. We found that industry-related, quality assurance, and empirical studies often originate or maintain new streams of research.
Keywords: Cross-citations; flossmole cited; graph; literature review; network; research; Systematic Mapping Study

Cliff Walls: An Analysis of Monolithic Commits Using Latent Dirichlet Allocation - Pratt, Landon J.; MacLean, Alexander C.; Knutson, Charles D.; Ringger, Eric K. (Open Source Systems: Grounding Research (OSS 2011), 2011)
Artifact-based research provides a mechanism whereby researchers may study the creation of software yet avoid many of the difficulties of direct observation and experimentation. However, there are still many challenges that can affect the quality of artifact-based studies, especially those studies examining software evolution. Large commits, which we refer to as “Cliff Walls,” are one significant threat to studies of software evolution because they do not appear to represent incremental development. We used Latent Dirichlet Allocation to extract topics from over 2 million commit log messages, taken from 10,000 SourceForge projects. The topics generated through this method were then analyzed to determine the causes of over 9,000 of the largest commits. We found that branch merges, code imports, and auto-generated documentation were significant causes of large commits. We also found that corrective maintenance tasks, such as bug fixes, did not play a significant role in the creation of large commits.
Keywords: artifacts; commit; cvs; LDA; lines of code; log files; scm; sloc; sourceforge; version control

A comparative study of challenges in integrating Open Source Software and Inner Source Software - Stol, Klaas-Jan; Ali Babar, Muhammad; Avgeriou, Paris; Fitzgerald, Brian (Information and Software Technology, 2011)
Context Several large software-developing organizations have adopted Open Source Software development (OSSD) practices to develop in-house components that are subsequently integrated into products. This phenomenon is also known as “Inner Source”. While there have been several reports of successful cases of this phenomenon, little is known about the challenges that practitioners face when integrating software that is developed in such a setting. Objective The objective of this study was to shed light on challenges related to building products with components that have been developed within an Inner Source development environment. Method Following an initial systematic literature review to generate seed category data constructs, we performed an in-depth exploratory case study in an organization that has a significant track record in the implementation of Inner Source. Data was gathered through semi-structured interviews with participants from a range of divisions across the organization. Interviews were transcribed and analyzed using qualitative data analysis techniques. Results We have identified a number of challenges and approaches to address them, and compared the findings to challenges related to development with OSS products reported in the literature. We found that many challenges identified in the case study could be mapped to challenges related to integration of OSS. Conclusion The results provide important insights into common challenges of developing with OSS and Inner Source and may help organizations to understand how to improve their software development practices by adopting certain OSSD practices. The findings also identify the areas that need further research. Highlights ► We performed a case study that has adopted Open Source development practices. ► We studied the challenges encountered and approaches taken by the organization. ► We performed a systematic review to identify challenges related to Open Source. ► We compared the findings from the review to the findings from the case study. ► Most identified challenges could be mapped to the findings from the literature.
Keywords: Open Source Software; Inner Source; Software development; Challenges; Case study; Empirical studies

Developing Architectural Documentation for the Hadoop Distributed File System - Bass, Len; Kazman, Rick; Ozkaya, Ipek (Open Source Systems: Grounding Research (OSS 2011), 2011)
Many open source projects are lacking architectural documentation that describes the major pieces of the system, how they are structured, and how they interact. We have produced architectural documentation for the Hadoop Distributed File System (HDFS), a major open source project. This paper describes our process and experiences in developing this documentation. We illustrate the documentation we have produced and how it differs from existing documentation by describing the redundancy mechanisms used in HDFS for reliability.

Do comments explain codes adequately? - Mizuno, Osamu; Hirata, Yukinao (Proceedings of the 8th working conference on Mining software repositories - MSR '11, 2011)
Comment lines in the software source code include descriptions of codes, usage of codes, copyrights, unused codes, comments, and so on. It is required for comments to explain the content of written code adequately, since the wrong description in the comment may causes further bug and confusion in maintenance. In this paper, we try to clarify a research question: "In which projects do comments describe the code adequately?" To answer this question, we selected the group 1 of mining challenge and used data obtained from Eclipse and Netbeans. Since it is difficult to answer the above question directly, we define the distance between codes and comments. By utilizing the fault-prone module prediction technique, we can answer the alternative question from the data of two projects. The result shows that Eclipse project has relatively adequate comments.
Keywords: comments; eclipse; msr challenge; netbeans; prediction

Do time of day and developer experience affect commit bugginess - Tan, Lin; Lam, Patrick; Eyolfson, Jon (Proceedings of the 8th working conference on Mining software repositories - MSR '11, 2011)
Modern software is often developed over many years with hundreds of thousands of commits. Commit metadata is a rich source of social characteristics, including the commit's time of day and the experience and commit frequency of its author. The "bugginess" of a commit is also a critical property of that commit. In this paper, we investigate the correlation between a commit's social characteristics and its "bugginess"; such results can be very useful for software developers and software engineering researchers. For instance, developers or code reviewers might be well-advised to thoroughly verify commits that are more likely to be buggy. In this paper, we study the correlation between a commit's bugginess and the time of day of the commit, the day of week of the commit, and the experience and commit frequency of the commit authors. We survey two widely-used open source projects: the Linux kernel and PostgreSQL. Our main findings include: (1) commits submitted between midnight and 4 AM (referred to as late-night commits) are significantly buggier and commits between 7 AM and noon are less buggy, implying that developers may want to double-check their own latenight commits; (2) daily-committing developers produce less-buggy commits, indicating that we may want to promote the practice of daily-committing developers reviewing other developers' commits; and (3) the bugginess of commits versus day-of-week varies for different software projects.

Effort estimation of FLOSS projects: a study of the Linux kernel - Capiluppi, Andrea; Izquierdo-Cortázar, Daniel (Empirical Software Engineering, 2011)
Empirical research on Free/Libre/Open Source Software (FLOSS) has shown that developers tend to cluster around two main roles: “core” contributors differ from “peripheral” developers in terms of a larger number of responsibilities and a higher productivity pattern. A further, cross-cutting characterization of developers could be achieved by associating developers with “time slots”, and different patterns of activity and effort could be associated to such slots. Such analysis, if replicated, could be used not only to compare different FLOSS communities, and to evaluate their stability and maturity, but also to determine within projects, how the effort is distributed in a given period, and to estimate future needs with respect to key points in the software life-cycle (e.g., major releases). This study analyses the activity patterns within the Linux kernel project, at first focusing on the overall distribution of effort and activity within weeks and days; then, dividing each day into three 8-hour time slots, and focusing on effort and activity around major releases. Such analyses have the objective of evaluating effort, productivity and types of activity globally and around major releases. They enable a comparison of these releases and patterns of effort and activities with traditional software products and processes, and in turn, the identification of company-driven projects (i.e., working mainly during office hours) among FLOSS endeavors. The results of this research show that, overall, the effort within the Linux kernel community is constant (albeit at different levels) throughout the week, signalling the need of updated estimation models, different from those used in traditional 9am–5pm, Monday to Friday commercial companies. It also becomes evident that the activity before a release is vastly different from after a release, and that the changes show an increase in code complexity in specific time slots (notably in the late night hours), which will later require additional maintenance efforts.
Keywords: complexity; effort estimation; Effort models; mining software repositories; open source software

An Empirical Study of Open Source Software Usability - Raza, Arif; Capretz, Luiz Fernando; Ahmed, Faheem (International Journal of Open Source Software and Processes, 2011)
Recent years have seen a sharp increase in the use of open source projects by common novice users; Open Source Software (OSS) is thus no longer a reserved arena for software developers and computer gurus. Although user-centered designs are gaining popularity in OSS, usability is still not considered one of the prime objectives in many design scenarios. This paper analyzes industry users’ perception of usability factors, including understandability, learnability, operability, and attractiveness on OSS usability. The research model of this empirical study establishes the relationship between the key usability factors and OSS usability from industrial perspective. In order to conduct the study, a data set of 105 industry users is included. The results of the empirical investigation indicate the significance of the key factors for OSS usability.
Keywords: Survey

An empirical study of software architectures’ effect on product quality - Hansen, Klaus Marius; Jonasson, Kristjan; Neukirchen, Helmut (Journal of Systems and Software, 2011)
Software architecture is concerned with the structure of software systems and is generally agreed to influence software quality. Even so, little empirical research has been performed on the relationship between software architecture and software quality. Basedon 1,141 open source Java projects, we calculate three software architecture metrics (measuring classes per package, normalizeddistance, and a new metric introduced by us concerning the excess of coupling degree) and analyze to which extent these metricsare related to product metrics (defect ratio, download rate, methods per class, and method complexity). We conclude that there area number of significant relationships between product metrics and architecture metrics. In particular, the number of open defectsdepends significantly on all our architecture measures.
Keywords: flossmole cited; java

Entering the circle of trust - Mani, Senthil; Sinha, Saurabh; Sinha, Vibha Singhal (Proceeding of the 8th working conference on Mining software repositories - MSR '11, 2011)
The success of an open-source project depends to a large degree on the proactive and constructive participation by the developer community. An important role that developers play in a project is that of a code committer. However, code-commit privilege is typically restricted to the core group of a project. In this paper, we study the phenomenon of the induction of external developers as code committers. The trustworthiness of an external developer is one of the key factors that determines the granting of commit privileges. Therefore, we formulate different hypotheses to explain how the trust is established in practice. To investigate our hypotheses, we developed an automated approach based on mining code repositories and bug-tracking systems. We implemented the approach and performed an empirical study, using the Eclipse projects, to test the hypotheses. Our results indicate that, most frequently, developers establish trust and credibility in a project by contributing to the project in a non-committer role. Moreover, the employing organization of a developer is another factor--although a less significant one--that influences trust.
Keywords: bug tracking; bug tracking system; commits; committers; core; developers; eclipse; trust

Experiences Mining Open Source Release Histories - Jason Tsay; Wright, Hyrum; Perry, Dewayne (International Conference on Software and Systems Process (ICSSP 2011), 2011)
Software releases form a critical part of the life cycle of a software project. Typically, each project produces releases in its own way, using various methods of versioning, archiving, announcing and publishing the release. Understanding the release history of a software project can shed light on the project history, as well as the release process used by that project, and how those processes change. However, many factors make automating the retrieval of release history information difficult, such as the many sources of data, a lack of relevant standards and a disparity of tools used to create releases. In spite of the large amount of raw data available, no attempt has been made to create a release history database of a large number of projects in the open source ecosystem. This paper presents our experiences, including the tools, techniques and pitfalls, in our early work to create a software release history database which will be of use to future researchers who want to study and model the release engineering process in greater depth.
Keywords: doap; flossmole cited; life cycle; release engineering; release history; release management; releases

Exploring, exposing, and exploiting emails to include human factors in software engineering - Bacchelli, Alberto (Companion to the Proceedings of the 33rd International Conference on Software Engineering, 2011)
Researchers mine software repositories to support software maintenance and evolution. The analysis of the structured data, mainly source code and changes, has several benefits and offers precise results. This data, however, leaves communication in the background, and does not permit a deep investigation of the human factor, which is crucial in software engineering. Software repositories also archive documents, such as emails or comments, that are used to exchange knowledge among people - we call it "people-centric information." By covering this data, we include the human factor in our analysis, yet its unstructured nature makes it currently sub-exploited. Our work, by focusing on email communication and by implementing the necessary tools, investigates methods for exploring, exposing, and exploiting unstructured data. We believe it is possible to close the gap between development and communication, extract opinions, habits, and views of developers, and link implementation to its rationale; we see in a future where software analysis and development is routinely augmented with people-centric information.
Keywords: email communication; toolset; unstructured data

Factors Affecting the Development of Absorptive Capacity in the Adoption of Open Source Software - Ven, Kris; De Bruyn, Peter (International Journal of Open Source Software and Processes, 2011)
Previous research has shown that the knowledge that is available to an organization is an important factor influencing the adoption of open source software (OSS). Hence, it is important that organizations develop their absorptive capacity in order to successfully adopt OSS. Absorptive capacity refers to the ability of an organization to acquire, assimilate, and exploit new knowledge. However, no study has specifically investigated how organizations can develop their absorptive capacity by acquiring knowledge about OSS. This paper addresses this gap in research by investigating the organizational knowledge assimilation process within the context of the adoption of OSS. Based on a case study conducted at the Flemish government, a framework that is grounded in literature and that illustrates which contextual factors influence the development of absorptive capacity in the context of the adoption of OSS was developed.
Keywords: adoption; government

FLOSS Project Effectiveness Measures - Kevin Crowston; Howison, James (Successful OSS Project Design and Implementation, 2011)
In this chapter, we develop and illustrate measures of the effectiveness of FLOSS projects. FLOSS is a broad term used to embrace software that is developed and released under either a “free software” or an “open source” license. While the free software and the open source movements are distinct, both kinds of licenses allow users to obtain and distribute the software’s original source without charge (software is “free as in beer”) and to inspect, modify, and redistribute modifications to the source code. While the open source movement views these freedoms pragmatically (as a development methodology), the free software movement emphasizes the meaning of “free as in speech,” which is captured by the French/Spanish libre, and one of their methods of supporting those freedoms is “copyleft,” famously embodied in the General Public License, meaning that derivative works must be made available under the same license terms as the original. This chapter focuses on development practices in distributed work, which are largely shared across the movements. For example, many (though by no means all) FLOSS developers contribute to projects as volunteers without working for a common organization or being paid. We therefore use the acronym FLOSS to refer collectively to free/libre and open source software. It is important to develop measures of effectiveness for FLOSS projects for at least two reasons. First, having such measures should be useful for FLOSS project managers in assessing their projects. In some cases, FLOSS projects are sponsored by third parties, so measures are useful for sponsors to understand the return on their investment. Second, FLOSS is an increasingly visible and copied mode of systems development. Millions of users depend on FLOSS systems such as Linux and on the Internet, which is itself heavily dependent on FLOSS tools, but as Scacchi (2002a, p. 1) notes, “little is known about how people in these communities coordinate software development across different settings, or about what software processes, work practices, and organizational contexts are necessary to their success.” An EU/NSF workshop on priorities for FLOSS research identified the need both for learning from open source modes of organization and production that could perhaps be applied to other areas and for a concerted effort on open source in itself, for itself (Ghosh 2002). But to be able to learn from teams that are working well, we need to have a definition of working well. In the following sections of the chapter, we will first discuss several measures of project effectiveness, and then the procedure we used to obtain data with which to operationalize these measures, followed by the details of the analysis approach. We then present the results of this analysis and discuss the implications of these results. We then illustrate how these measures can be used to compare projects as part of a research study. We conclude with some suggestions for future research.

FLOSSSim: Understanding the Free/Libre Open Source Software (FLOSS) Development Process through Agent-Based Modeling - Radtke, Nicholas P. (Arizona State University, 2011)
Free/Libre Open Source Software (FLOSS) is the product of volunteers collaborating to build software in an open, public manner. The large number of FLOSS projects, combined with the data that is inherently archived with this online process, make studying this phenomenon attractive. Some FLOSS projects are very functional, well-known, and successful, such as Linux, the Apache Web Server, and Firefox. However, for every successful FLOSS project there are 100's of projects that are unsuccessful. These projects fail to attract sufficient interest from developers and users and become inactive or abandoned before useful functionality is achieved. The goal of this research is to better understand the open source development process and gain insight into why some FLOSS projects succeed while others fail. This dissertation presents an agent-based model of the FLOSS development process. The model is built around the concept that projects must manage to attract contributions from a limited pool of participants in order to progress. In the model developer and user agents select from a landscape of competing FLOSS projects based on perceived utility. Via the selections that are made and subsequent contributions, some projects are propelled to success while others remain stagnant and inactive. Findings from a diverse set of empirical studies of FLOSS projects are used to formulate the model, which is then calibrated on empirical data from multiple sources of public FLOSS data. The model is able to reproduce key characteristics observed in the FLOSS domain and is capable of making accurate predictions. The model is used to gain a better understanding of the FLOSS development process, including what it means for FLOSS projects to be successful and what conditions increase the probability of project success. It is shown that FLOSS is a producer-driven process, and project factors that are important for developers selecting projects are identified. In addition, it is shown that projects are sensitive to when core developers make contributions, and the exhibited bandwagon effects mean that some projects will be successful regardless of competing projects. Recommendations for improving software engineering in general based on the positive characteristics of FLOSS are also presented.

Forge.mil: A Case Study for Utilizing Open Source Methodologies Inside of Government - Martin, Guy; Lippold, Aaron (Open Source Systems: Grounding Research (OSS 2011), 2011)
In late 2008, DISA (Defense Information Systems Agency), the global IT arm of the US Department of Defense, embarked upon a project to create an internal collaboration and software application lifecycle management system. Beyond simply fielding yet another tool, the Forge.mil effort was designed to fundamentally change the way the DoD developed and acquired software technology and systems. The method of this change was the application of Open Source principles inside of the larger DoD community, including ideas such as meritocracy and code sharing, as well as Agile and collaborative software development. This lightning talk will explain the rationale behind Forge.mil, how it was developed using Open Source principles, and how it continues to influence technology acquisition within the DoD in both practice and policy changes.

Framing the Conundrum of Total Cost of Ownership of Open Source Software - Maha Shaikh; Cornford, Tony (Open Source Systems: Grounding Research (OSS 2011), 2011)
This paper reflects the results of phase I of our study on the total cost of ownership (TCO) of open source software adoption. Not only have we found TCO to be an intriguing issue but it is contentious, baffling and each company approaches it in a distinctive manner (and sometimes not at all). In effect it is a conundrum that needs unpacking before it can be explained and understood. Our paper discusses the components of TCO as total cost of ownership and total cost of acquisition (and besides). Using this broad dichotomy and its various components we then analyze our data to make sense of procurement decisions in relation to open source software in the public sector and private companies.
Keywords: benefits; exit costs; open source software; software adoption; Survey; tco; total cost of ownership

Ginga-J: An Open Java-Based Application Environment for Interactive Digital Television Services - Kulesza, Raoni; Lima, Jefferson F.A.; Guedes, Alan L.; Junior, Lucenildo L.A.; Meira, Silvio R.L.; Filho, Guido L.S. (Open Source Systems: Grounding Research (OSS 2011), 2011)
This paper aims to present a Ginga-J’s reference implementation. Although based on a particular platform, the implementation not only works as a proof of concept, but also raised several issues and difficulties on the software architecture project that should be taken into account to ease extensibility and porting to other platforms. Ginga is the standard middleware for the Brazilian DTV System. Its imperative environment (Ginga-J) is based on new JavaDTV specification and mandatory for fixed terrestrial receptors.

Health Informatics: The Relevance of Open Source and Multilevel Modeling - Cavalini, Luciana T.; Cook, Timothy W. (Open Source Systems: Grounding Research (OSS 2011), 2011)
Health information features significant spatial-temporal and domain complexities, which brings challenges to the implementation of patient-centered, interoperable and semantically coherent healthcare information systems. This position paper supports the idea that the multilevel modeling approach is essential to ensure interoperability at the semantic level, but true interoperability is only achieved by the adoption of open standards, and open source implementations are needed for promote competition based on software quality. The Multilevel Healthcare Information Modelling (MLHIM) specifications are presented as the fully open source multilevel modeling reference implementation, and best practices for the development of multilevel- based open source healthcare applications are suggested.
Keywords: Health informatics; multilevel modeling; open source software

A Historical Account of the Value of Free and Open Source Software: From Software Commune to Commercial Commons (Open Source Systems: Grounding Research (OSS 2011), 2011)
Free and open source software has transformed from what has been characterized as a resistance movement against proprietary software to become a commercially viable form of software development, integrated in various forms with proprietary software business. In this paper we explain this development as a dependence on historical formations, shaped by different ways of justifying the use of open source during different periods of time. These formations are described as arrangements of different justificatory logics within a certain time frame or a certain group of actors motivating the use of free and open source software by referring to different potentialities. The justificatory arrangements change over time, and tracing these changes makes it easier to understand how the cultural, economic and social practices of open source movements are currently being absorbed and adopted in a commercial context.
Keywords: Free and Open Source Software; Historical approach; Justification

How do developers blog? - Maalej, Walid; Pagano, Dennis (Proceedings of the 8th working conference on Mining software repositories - MSR '11, 2011)
We report on an exploratory study, which aims at understanding how software developers use social media compared to conventional development infrastructures. We analyzed the blogging and the committing behavior of 1,100 developers in four large open source communities. We observed that these communities intensively use blogs with one new entry about every 8 hours. A blog entry includes 14 times more words than a commit message. When analyzing the content of the blogs, we found that most popular topics represent high-level concepts such as functional requirements and domain concepts. Source code related topics are covered in less than 15% of the posts. Our results also show that developers are more likely to blog after corrective engineering and management activities than after forward engineering and re-engineering activities. Our findings call for a hypothesis-driven research to further understand the role of social media in software engineering and integrate it into development processes and tools.
Keywords: blog; communication; developer; eclipse; gnome; LDA; postgres; python

Impact of Stakeholder Type and Collaboration on Issue Resolution Time in OSS Projects - Duc, Ach Nguyen; Cruzes, Daniela S.; Ayala, Claudia; Conradi, Reidar (Open Source Systems: Grounding Research (OSS 2011), 2011)
Initialized by a collective contribution of volunteer developers, Open source software (OSS) attracts an increasing involvement of commercial firms. Many OSS projects are composed of a mix group of firm-paid and volunteer developers, with different motivations, collaboration practices and working styles. As OSS development consists of collaborative works in nature, it is important to know whether these differences have an impact on collaboration between difference types of stakeholders, which lead to an influence in the project outcomes. In this paper, we empirically investigate the firm-paid participation in resolving OSS evolution issues, the stakeholder collaboration and its impact on OSS issue resolution time. The results suggest that though a firm-paid assigned developer resolves much more issues than a volunteer developer does, there is no difference in issue resolution time between them. Besides, the more important factor that influences the issue resolution time comes from the collaboration among stakeholders rather than from individual characteristics.
Keywords: COLLABORATION; companies; coordination; defects; feature requests; geronimo; jira; qpid; qt; social network analysis; volunteer

The Importance of Architectural Knowledge in Integrating Open Source Software - Stol, Klaas-Jan; Ali Babar, Muhammad; Avgeriou, Paris (Open Source Systems: Grounding Research (OSS 2011), 2011)
Open Source Software (OSS) is increasingly used in Component-Based Software Development (CBSD) of large software systems. An important issue in CBSD is selection of suitable components. Various OSS selection methods have been proposed, but most of them do not consider the software architecture aspects of OSS products. The Software Architecture (SA) research community refers to a product’s architectural information, such as design decisions and underlying rationale, and used architecture patterns, as Architecture Knowledge (AK). In order to investigate the importance of AK of OSS components in integration, we conducted an exploratory empirical study. Based on in-depth interviews with 12 IT professionals, this paper presents insights into the following questions: 1) what AK of OSS is needed? 2) Why is AK of OSS needed? 3) Is AK of OSS generally available? And 4) what is the relative importance of AK? Based on these new insights, we provide a research agenda to further the research field of software architecture in OSS.
Keywords: architectural knowledge; component-based development; Open Source Software integration; OSS Integrator; software architecture; Survey

Improving open source software patch contribution process: methods and tools - Bhuricha Deen Sethanandha (Proceedings of the 33rd International Conference on Software Engineering, 2011)
The patch contribution process (PCP) is very important to the sustainability of OSS projects. Nevertheless, there are several issues on patch contribution in mature OSS projects, which include time consuming process, lost and ignored patches, slow review process. These issues are recognized by researchers and OSS projects, but have not been addressed. In this dissertation, I apply Kanban method to guide process improvement and tools development to reduce PCP cycle time.
Keywords: coordination; free software; kanban; lean methods; open source software; patches; productivity

Java generics adoption - Christian Bird; Murphy-Hill, Emerson; Parnin, Chris (Proceedings of the 8th working conference on Mining software repositories - MSR '11, 2011)
Support for generic programming was added to the Java language in 2004, representing perhaps the most significant change to one of the most widely used programming languages today. Researchers and language designers anticipated this addition would relieve many long-standing problems plaguing developers, but surprisingly, no one has yet measured whether generics actually provide such relief. In this paper, we report on the first empirical investigation into how Java generics have been integrated into open source software by automatically mining the history of 20 popular open source Java programs, traversing more than 500 million lines of code in the process. We evaluate five hypotheses, each based on assertions made by prior researchers, about how Java developers use generics. For example, our results suggest that generics do not significantly reduce the number of type casts and that generics are usually adopted by a single champion in a project, rather than all committers.
Keywords: commits; generics; java; source code; version history

Joining Free/Open Source Software Communities: An Analysis of Newbies' First Interactions on Project Mailing Lists - Jensen, Carlos; King, Scott; Kuechler, Victor (2011 44th Hawaii International Conference on System Sciences (HICSS 2011), 2011)
Free/Open source software (FOSS) is an important part of the IT ecosystem. Due to the voluntary nature of participation, continual recruitment is key to the growth and sustainability of these communities. It is therefore important to understand how and why potential contributors fail in the process of transitioning from user to contributor. Most newcomers, or "newbies", have their first interaction with a community through a mailing list. To understand how this first contact influences future interactions, we studied eight mailing lists across four FOSS projects: MediaWiki, GIMP, PostgreSQL, and Subversion. We analyzed discussions initiated by newbies to determine the effect of gender, nationality, politeness, helpfulness and timeliness of response. We found that nearly 80% of newbie posts received replies, and that receiving timely responses, especially within 48 hours, was positively correlated with future participation. We also found that while the majority of interactions were positive, 1.5% of responses were rude or hostile.
Keywords: email; email archive; gimp; mailing list; mediawiki; postgresql; subversion

Knowledge Homogeneity and Specialization in the Apache HTTP Server Project - MacLean, Alexander C.; Pratt, Landon J.; Knutson, Charles D.; Ringger, Eric K. (Open Source Systems: Grounding Research (OSS 2011), 2011)
We present an analysis of developer communication in the Apache HTTP Server project. Using topic modeling techniques we expose latent conceptual sub-communities arising from developer specialization within the greater developer population. However, we found that among the major contributors to the project, very little specialization exists. We present theories to explain this phenomenon, and suggest further research.
Keywords: apache; commits; developer; email; email archive; LDA; mailing list; revision control; revision history; scm; social network analysis; specialization; subversion; svn

KommGame: A Reputation Environment for Teaching Open Source Software - Goduguluri, Veerakishore; Kilamo, Terhi; Hammouda, Imed (Open Source Systems: Grounding Research (OSS 2011), 2011)
The importance of teaching open source software in universities is increasing with the advent of open source as a development and business model. A novel, student centric approach of teaching open source was tried out at Tampere University of Technology where a new environment called KommGame was introduced to assist in teaching open source development. This environment includes a reputation system to motivate learners to participate. In this paper, we present our approach of teaching open source and how the KommGame environment was employed to teach open source software.

Libre Software as an Innovation Enabler in India: Experiences of a Bangalorian Software SME - Henttonen, Katja (Open Source Systems: Grounding Research (OSS 2011), 2011)
Free/Libre and open source software (FLOSS) has been advocated for its presumed capacity to support native software industries in developing countries. It is said to create new spaces for exploration and to lower entry barriers to mature software markets, for example. However, little empirical research has been conducted concerning FLOSS business in a developing country setting and, thus, there is not much evidence to support or refute these claims. This paper presents a business case study conducted in India, a country branded as a 'software powerhouse' of the developing world. The findings show how FLOSS has opened up significant opportunities for the case company, especially in terms of improving its innovative capability and upgrading in the software value chain. On the other hand, they also highlight some challenges to FLOSS involvement that rise specifically from the Indian context.
Keywords: free software; India; INNOVATION; open source; software business

License Update and Migration Processes in Open Source Software Projects - Chris Jensen; Walt Scacchi (Open Source Systems: Grounding Research (OSS 2011), 2011)
Open source software (OSS) has increasingly been the subject of research efforts. Central to this focus is the nature under which the software can be distributed, used, and modified and the causes and consequent effects on software development, usage, and distribution. At present, we have little understanding of, what happens when these licenses change, what motivates such changes, and how new licenses are created, updated, and deployed. Similarly, little attention has been paid to the agreements under which contributions are made to OSS projects and the impacts of changes to these agreements. We might also ask these same questions regarding the licenses governing how individuals and groups contribute to OSS projects. This paper focuses on addressing these questions with case studies of processes by which the Apache Software Foundation's creation and migration to Version 2.0 of the Apache Software License and the NetBeans project's migration to the Joint Licensing Agreement.
Keywords: apache; case study; email; email archive; license evolution; mailing list; netbeans; open source; process

Modding as an Open Source Approach to Extending Computer Game Systems - Walt Scacchi (Open Source Systems: Grounding Research (OSS 2011), 2011)
This paper examines what is known so far about the role of open source software development within the world of game mods and modding practices. Game modding has become a leading method for developing games by customizing or creating OSS extensions to game software in general, and to proprietary closed source software games in particular. What, why, and how OSS and CSS come together within an application system is the subject for this study. The research method is observational and qualitative, so as to highlight current practices and issues that can be associated with software engineering and game studies foundations. Numerous examples of different game mods and modding practices are identified throughout.
Keywords: games; modding; mods

The onion patch: migration in open source ecosystems - Jergensen, Corey; Sarma, Anita; Wagstrom, Patrick (Proceedings of the 19th ACM SIGSOFT symposium and the 13th European conference on Foundations of software engineering, 2011)
Past research established that individuals joining an Open Source community typically follow a socialization process called "the onion model": newcomers join a project by first contributing at the periphery through mailing list discussions and bug trackers and as they develop skill and reputation within the community they advance to central roles of contributing code and making design decisions. However, the modern Open Source landscape has fewer projects that operate independently and many projects under the umbrella of software ecosystems that bring together projects with common underlying components, technology, and social norms. Participants in such an ecosystems may be able to utilize a significant amount of transferrable knowledge when moving between projects in the ecosystem and, thereby, skip steps in the onion model. In this paper, we examine whether the onion model of joining and progressing in a standalone Open Source project still holds true in large project ecosystems and how the model might change in such settings.
Keywords: contribution model; open source software; project ecosystem

The Ontology of the OSS Business Model - Lakka, Spyridoula; Stamati, Teta; Michalakelis, Christos; Martakos, Dracoulis (International Journal of Open Source Software and Processes, 2011)
This study focuses on theory building providing a holistic conceptual framework that consists of an ontology based OSS business model and an OSS business model taxonomy. The study extends existing theory in OSS business models and corresponding taxonomies, based on the structured-case methodological approach. An exploratory study is conducted in two research cycles, for the identification, validation, and evaluation of the critical constructs of an OSS business model. Results reveal that OSS business models differ from traditional software business models, having specific features that affect the software value chain, the infrastructure, and the revenue model of an OSS oriented firm.

Open Source and Open Data: Business Perspectives from the Frontline - Juho Lindman; Tammisto, Yulia (Open Source Systems: Grounding Research (OSS 2011), 2011)
Open data initiatives on governmental data seem often to be linked to small software companies, which also use and release software under OSS licenses. This paper calls for more research to understand the similarities between open data and open source software vendors. We build a theoretical linkage between the more established OSS research and emerging research on open data in the context of small software companies.

Open Source Software for Model Driven Development: A Case Study - Gamalielsson, Jonas; Lundell, Björn; Mattsson, Anders (Open Source Systems: Grounding Research (OSS 2011), 2011)
Model Driven Development (MDD) is widely used in the embedded systems domain, and many proprietary and Open Source tools exist that support MDD. The potential for sustainability of such tools needs to assessed prior to any organisational adoption. In this paper we report from a case study conducted in a consultancy company context aiming to investigate Open Source tools for MDD. For the company it was interesting to explore the two Open Source modelling tools Topcased and Papyrus for potential adoption. The focus for our case study is on assessing the health of the ecosystems for the two investigated Open Source projects by means of quantitative analysis of publically available data sources about Open Source projects. The health of ecosystems is an important prerequisite for a long term sustainable OSS (Open Source Software) tool-chain in the MDD area, which can aid strategic decision making for potential adoption within a company context. We have established details on the extent to which developers and users are active in two specific OSS ecosystems, and identified organisational influence for both ecosystems. We find that the investigated tools are promising regarding the health of their ecosystems, and a natural next step for the company would be to proceed with a pilot study in order to analyse the effectiveness of the investigated tools in company contexts.

OSS-TMM - Morasca, Sandro; Taibi, Davide; Tosi, Davide (International Journal of Open Source Software and Processes, 2011)
Open Source Software (OSS) products do not usually follow traditional software engineering development paradigms. Specifically, testing activities in OSS development may be quite different from those carried out in Closed Source Software (CSS) development. As testing and verification require a good deal of resources in OSS, it is necessary to have ways to assess and improve OSS testing processes. This paper provides a set of testing guidelines and issues that OSS developers can use to decide which testing techniques make most sense for their OSS products. This paper 1) provides a checklist that helps OSS developers identify the most useful testing techniques according to the main characteristics of their products, and 2) outlines a proposal for a method that helps assess the maturity of OSS testing processes. The method is a proposal of a Maturity Model for testing processes (called OSS-TMM). To show its usefulness, the authors apply the method to seven real-life projects. Specifically, the authors apply the method to BusyBox, Apache Httpd, and Eclipse Test & Performance Tools Platform to show how the checklist supports and guides the testing process of these OSS products.
Keywords: testing

Package Upgrade Robustness: An Analysis for GNU/Linux Package Management Systems - Thomson, John; Guerrriro, Andre; Paulo Trezentos; Johnson, Jeff (Open Source Systems: Grounding Research (OSS 2011), 2011)
GNU/Linux systems are today used in servers, desktops, mobile and embedded devices. One of the critical operations is the installation and maintenance of software packages in the system. Currently there are no frameworks or tools for evaluating Package Management Systems (PMSs), such as RPM, in Linux and for measuring their reliability. The authors perform an analysis of the robustness of the RPM engine and discuss some of the current limitations. This article contributes to the enhancement of Software Reliability in Linux by providing a framework and testing tools under an open source license. These tools can easily be extended to other PMSs such as DEB packages or Gentoo Portage.
Keywords: linux; package management; rpm

Path dependent stochastic models to detect planned and actual technology use: A case study of OpenOffice - Rossi, Bruno; Russo, Barbara; Succi, Giancarlo (Information and Software Technology, 2011)
Abstract Context Adopting IT innovation in organizations is a complex decision process driven by technical, social and economic issues. Thus, those organizations that decide to adopt innovation take a decision of uncertain success of implementation, as the actual use of a new technology might not be the one expected. The misalignment between planned and effective use of innovation is called assimilation gap. Objective This research aims at defining a quantitative instrument for measuring the assimilation gap and applying it to the case of the adoption of OSS. Method In this paper, we use the theory of path dependence and increasing returns of Arthur. In particular, we model the use of software applications (planned or actual) by stochastic processes defined by the daily amounts of files created with the applications. We quantify the assimilation gap by comparing the resulting models by measures of proximity. Results We apply and validate our method to a real case study of introduction of OpenOffice. We have found a gap between the planned and the effective use despite well-defined directives to use the new OS technology. These findings suggest a need of strategy re-calibration that takes into account environmental factors and individual attitudes. Conclusions The theory of path dependence is a valid instrument to model the assimilation gap provided information on strategy toward innovation and quantitative data on actual use are available.
Keywords: Actual use of technology; Path dependence; Technology adoption; Urn models

Preparing FLOSS for Future Network Paradigms: A Survey on Linux Network Management - Matos, Alfredo; Thomson, John; Paulo Trezentos (Open Source Systems: Grounding Research (OSS 2011), 2011)
Operating system tools must fulfill the requirements generated by the advances in networking paradigms. To understand the current state of the Free, Libre and Open Source Software (FLOSS) ecosystem, we present a survey on the main tools used to manage and interact with the network, and how they are organized in Linux-based operating systems. Based on the survey results, we present a reference Linux network stack that can serve as the basis for future heterogeneous network environments, contributing towards a standardized approach in Linux. Using this stack, and focusing on dynamic and spontaneous network interactions, we present an evolution path for network related technologies, contributing to Linux as a network research operating system and to FLOSS as a whole.
Keywords: linux; networking; Survey

Process Mining Software Repositories - Poncin, Wouter; Serebrenik, Alexander; Brand, Mark van den (15th European Conference on Software Maintenance and Reengineering (CSMR 2011), 2011)
Software developers’ activities are in general recorded in software repositories such as version control systems, bug trackers and mail archives. While abundant information is usually present in such repositories, successful information extraction is often challenged by the necessity to simultaneously analyze different repositories and to combine the information obtained. We propose to apply process mining techniques, originally developed for business process analysis, to address this challenge. However, in order for process mining to become applicable, different software repositories should be combined, and “related” software development events should be matched: e.g., mails sent about a file, modifications of the file and bug reports that can be traced back to it. The combination and matching of events has been implemented in FRASR (FRamework for Analyzing Software Repositories), augmenting the process mining framework ProM. FRASR has been successfully applied in a series of case studies addressing such aspects of the development process as roles of different developers and the way bug reports are handled.
Keywords: amsn; email; email archives; gcc; mailing list; Process mining; software repositories

On qualitative methodologies and dispersed communities: Reflections on the process of investigating an open source community - Sigfridsson, Anders; Sheehan, Anne (Information and Software Technology, 2011)
Context Qualitative methodologies hold much potential for building an understanding of the principles and practices of free and open source software (FOSS) communities. Yet there is a scarcity in the literature of discussions focused on the practical and methodological challenges of this particular research context. Objective This paper formulates and addresses a number of questions regarding the applicability of qualitative methodologies for the study of FOSS communities. It reflects on the challenges of such approaches as seen in previous research efforts and discusses how they manifest in research practice through a thorough description of a case study of a community called PyPy. Method The paper primarily discusses interpretive research approaches which are based on ethnographic data collection methods. The study under discussion was an exploratory case study utilizing multiple methods, including participant observation, virtual ethnography, and open-ended questionnaires. Grounded Theory was used for data analysis. Results Two broad sets of challenges are highlighted in relation to the multidimensionality of the FOSS phenomenon and the difficulty of qualitative analysis of activities in long-term context. Additional issues identified relate to potential problems with focus and the need for reflexivity, but also to the extent of the study and the importance of maintaining an active relationship with the core community group. Conclusion This paper provides an overview – grounded in practical research experience and linked to insights from the literature – of methodological issues in the specific research area of qualitative studies of FOSS communities, which up until now has been lacking.
Keywords: case study; Collaborative practice; Distributed software development; Free open source communities; Qualitative methodologies

A Review of Tool Support for User-Related Communication in FLOSS Development - Rantalinen, Aapo; Hedberg, Henrik; Iivari, Netta (Open Source Systems: Grounding Research (OSS 2011), 2011)
Free/Libre/Open Source Software (FLOSS) projects rely on Internet tools for communication and in coordinating their work. Communication between developers is well supported in FLOSS projects, but user-developer communication has proven out to be challenging. This paper examines the following questions: ”What kinds of means for communication exist in FLOSS projects for user-developer communication? What kinds of means should there be?” We have carried out a literature review addressing communication in FLOSS projects, and contrasted the findings with Human-Computer Interaction (HCI) literature on user-developer communication. HCI literature indicates that user-developer communication is needed during requirements construction, design and evaluation tasks, and HCI specialists are needed for orchestrating the communication and the user related tasks. Communication during the evaluation task is somewhat supported in FLOSS projects, but design and requirements construction are badly in need for support, even though ideas have already been presented. In addition, HCI specialists are in need of different kinds of communication support in FLOSS projects.
Keywords: Free/Libre/Open Source Software; Human-Computer Interaction; literature review; Tool Support; User-Developer Communication

The search for a research method for studying OSS process innovation - Prechelt, Lutz; Oezbek, Christopher (Empirical Software Engineering, 2011)
Medium-sized, open-participation Open Source Software (OSS) projects do not usually perform explicit software process improvement on any routine basis. It would be useful to understand how to get such a project to accept a process improvement proposal and hence to perform process innovation. We want to determine an effective and feasible qualitative research method for studying the above question. We present (narratively) a case study of how we worked towards and eventually found such a research method. The case involves four attempts at collecting suitable data about innovation episodes (direct participation (twice), polling developers for episodes, manually finding episodes in mailing list archives) and the adaptation of the Grounded Theory data analysis methodology. Direct participation allows gathering rather rich data, but does not allow for observing a sufficiently large number of innovation episodes. Polling developers for episodes did not prove to be useful. Using mailing list archives to find data to be analyzed is both feasible and effective. We also describe how the data thus found can be analyzed based on the Grounded Theory Method with suitable adjustments. By-and-large, our findings ought to apply to studying various phenomena in OSS development processes that are similarly heavyweight and infrequent. However, specific details may block this possibility and we cannot predict which details that might be. The amount of effort involved in direct participation approaches to qualitative research can easily be underestimated. Also, survey approaches are not well-suited for many process issues in OSS, because too few developers are sufficiently process-conscious. An approach based on passive observation is a viable alternative in the OSS context due to the availability of large amounts of fairly complete archival data.
Keywords: argouml; Bochs; bugzilla; Flyspray; FreeDOS; gEDA; grounded theory; Grub; Innovation introduction; KVM; mailing list; Methodology; MonetDB; open source; Request Tracket; Rox; U-Boot; Xfce

A Secondary Data Archive for Code-Level Debian Metrics - Kozak, Carter; Squire, Megan (2011 Second International Workshop on Replication in Empirical Software Engineering Research (RESER), 2011)
In this paper, we describe a new process to collect, calculate, archive, and distribute interesting metrics for all the packages in the standard Debian GNU/Linux installation. Our method replicates and extends previous work done by other groups studying free and open source software systems (FLOSS) in three important ways. First, although there have been other previous studies that attempted to collect a large set of code-level metrics for a small set of projects, and there have been studies that generated a small set of metrics for the large Debian codebase, our project does both: we generate a larger set of metrics for the entire set of Debian packages. Second, our integration of new Debian metadata and additional code-level metrics not gathered before adds several additional layers for exploration. Finally, and most importantly, because we integrate our collection and analysis process into the automated FLOSSmole data store, we ensure timely, repeatable, and very easy comparison, replication and analysis by other groups. Thus our collection activity will continue in an automated fashion even after this paper is published, providing the foundation for additional studies to be conducted later, all freely accessible to any interested research group. After outlining our process, we discuss a few observations about the data, we outline some implications for the research community, and we present opportunities for further research.

Social interactions around cross-system bug fixings - Cerulo, Luigi; Cimitile, Marta; Di Penta, Massimiliano; Canfora, Gerardo (Proceedings of the 8th working conference on Mining software repositories - MSR '11, 2011)
Cross-system bug fixing propagation is frequent among systems having similar characteristics, using a common framework, or, in general, systems with cloned source code fragments. While previous studies showed that clones tend to be properly maintained within a single system, very little is known about cross-system bug management. This paper describes an approach to mine explicitly documented cross-system bug fixings, and to relate their occurrences to social characteristics of contributors discussing through the project mailing lists--e.g., degree, betweenness, and brokerage--as well as to the contributors' activity on source code. The paper reports results of an empirical study carried out on FreeBSD and OpenBSD kernels. The study shows that the phenomenon of cross-system bug fixing between these two projects occurs often, despite the limited overlap of contributors. The study also shows that cross-system bug fixings mainly involve contributors with the highest degree, betweenness and brokerage level, as well as contributors that change the source code more than others.
Keywords: bug fixing; bug tracking system; committers; email; email archives; freebsd; mailing list; openbsd

Sociomaterial bricolage: The creation of location-spanning work practices by global software developers - Johri, Aditya (Information and Software Technology, 2011)
Context Studies on global software development have documented severe coordination and communication problems among coworkers due to geographic dispersion and consequent dependency on technology. These problems are exacerbated by increase in the complexity of work undertaken by global teams. However, despite these problems, global software development is on the rise and firms are adopting global practices across the board, raising the question: What does successful global software development look like and what can we learn from its practitioners? Objective This study draws on practice-based studies of work to examine successful work practices of global software developers. The primary aim of this study was to understand how workers develop practices that allow them to function effectively across geographically dispersed locations. Method An ethnographically-informed field study was conducted with data collection at two international locations of a firm. Interview, observation and archival data were collected. A total of 42 interviews and 3 weeks of observations were conducted. Results Teams spread across different locations around the world developed work practices through sociomaterial bricolage. Two facets of technology use were necessary for the creation of these practices: multiplicity of media and relational personalization at dyadic and team levels. New practices were triggered by the need to achieve a work-life balance, which was disturbed by global development. Reflecting on my role as a researcher, I underscore the importance of understanding researchers’ own frames of reference and using research practices that mirror informants’ work practices. Conclusion Software developers on global teams face unique challenges which necessitate a shift in their work practices. Successful teams are able to create practices that span locations while still being tied to location based practices. Inventive use of material and social resources is central to the creation of these practices.
Keywords: Global software development; Interpretive analysis; interviews; Qualitative field study; Sociomaterial bricolage; Virtual teams; Work practices

Sociotechnical Coordination and Collaboration in Open Source Software - Christian Bird (Proceedings of the 27th IEEE International Conference on Software Maintenance, 2011)
Over the past decade, a new style of software development, termed open source software (OSS) has emerged and has originated large, mature, stable, and widely used software projects. As software continues to grow in size and complexity, so do development teams. Consequently, coordination and communication within these teams play larger roles in productivity and software quality. My dissertation focuses on the relationships between developers in large open source projects and how software affects and is affected by these relationships. Fortunately, source code repository histories, mailing list archives, and bug databases from OSS projects contain latent data from which we can reconstruct a rich view of a project over time and analyze these sociotechnical relationships. We present methods of obtaining and analyzing this data as well as the results of empirical studies whose goal is to answer questions that can help stakeholders understand and make decisions about their own teams. We answer questions such as “Do large OSS project really have a disorganized bazaar-like structure?” “What is the relationship between social and development behavior in OSS?” “How does one progress from a project newcomer to a full-fledged, core developer?” and others in an attempt to understand how large, successful OSS projects work and also to contrast them with projects in commercial settings.

Socio-technical developer networks: should we trust our measurements? - Meneely, Andrew; Williams, Laurie (Proceedings of the 33rd International Conference on Software Engineering, 2011)
Software development teams must be properly structured to provide effectiv collaboration to produce quality software. Over the last several years, social network analysis (SNA) has emerged as a popular method for studying the collaboration and organization of people working in large software development teams. Researchers have been modeling networks of developers based on socio-technical connections found in software development artifacts. Using these developer networks, researchers have proposed several SNA metrics that can predict software quality factors and describe the team structure. But do SNA metrics measure what they purport to measure? The objective of this research is to investigate if SNA metrics represent socio-technical relationships by examining if developer networks can be corroborated with developer perceptions. To measure developer perceptions, we developed an online survey that is personalized to each developer of a development team based on that developer's SNA metrics. Developers answered questions about other members of the team, such as identifying their collaborators and the project experts. A total of 124 developers responded to our survey from three popular open source projects: the Linux kernel, the PHP programming language, and the Wireshark network protocol analyzer. Our results indicate that connections in the developer network are statistically associated with the collaborators whom the developers named. Our results substantiate that SNA metrics represent socio-technical relationships in open source development projects, while also clarifying how the developer network can be interpreted by researchers and practitioners.
Keywords: developer network; developers; linux; linux kernel; PHP; social network analysis; Survey; wireshark

Something of a Potemkin Village? Acid2 and Mozilla’s Efforts to Comply with HTML4 - den Besten, Matthijs; Jean-Michel Dalle (Open Source Systems: Grounding Research (OSS 2011), 2011)
The real point here is that the Acid3 test isn’t a broad-spectrum standards-support test. It’s a showpiece, and something of a Potemkin village at that. Which is a shame, because what’s really needed right now is exhaustive test suites for specifications— XHTML, CSS, DOM, SVG.

Standing Situations and Issues of Open Source Policy in East Asian Nations: Outcomes of Open Source Research Workshop of East Asia - Noda, Tetsuo; Tansho, Terutaka; Coughlan, Shane (Open Source Systems: Grounding Research (OSS 2011), 2011)
East Asia nations have made some progress with this technology, and started to introduce OSS for e-government systems during the early part of this century. Many countries granted it a central role in their policies. The reasons for this include adoption of software based on standard specification, liberation from vender lock-in, or opposition to the market control of proprietary software. However, the primary reason is to reduce adoption costs for e-government systems. While this policy work is useful, there is a great deal more that needs to be done. The OSS adoption policy in each nation of East Asia must be accompanied by technological progress in domestic IT service industries or US multinationals will expand at the cost of local businesses. If this continues unchecked it will create a new form of lock-in for East Asian nations. Some Asian nations are trying to promote their domestic IT service industries, putting their OSS adoption policy to practical use, and this workshop will provide case studies of that work. It will also provide a forum for discussing current challenges and opportunities around both policy and practical implementation issues across Asia.

A study of language usage evolution in open source software - Gall, Harald; Karus, Siim (Proceedings of the 8th working conference on Mining software repositories - MSR '11, 2011)
The use of programming languages such as Java and C in Open Source Software (OSS) has been well studied. However, many other popular languages such as XSL or XML have received minor attention. In this paper, we discuss some trends in OSS development that we observed when considering multiple programming language evolution of OSS. Based on the revision data of 22 OSS projects, we tracked the evolution of language usage and other artefacts such as documentation files, binaries and graphics files. In these systems several different languages and artefact types including C/C++, Java, XML, XSL, Makefile, Groovy, HTML, Shell scripts, CSS, Graphics files, JavaScript, JSP, Ruby, Phyton, XQuery, OpenDocument files, PHP, etc. have been used. We found that the amount of code written in different languages differs substantially. Some of our findings can be summarized as follows: (1) JavaScript and CSS files most often co-evolve with XSL; (2) Most Java developers but only every second C/C++ developer work with XML; (3) and more generally, we observed a significant increase of usage of XML and XSL during recent years and found that Java or C are hardly ever the only language used by a developer. In fact, a developer works with more than 5 different artefact types (or 4 different languages) in a project on average.

Successful Reuse of Software Components: A Report from the Open Source Perspective - Capiluppi, Andrea; Boldyreff, Cornelia; Stol, Klaas-Jan (Open Source Systems: Grounding Research (OSS 2011), 2011)
A promising way of software reuse is Component-Based Software Development (CBSD). There is an increasing number of OSS products available that can be freely used in product development. However, OSS communities themselves have not yet taken full advantage of the “reuse mechanism”. Many OSS projects duplicate effort and code, even when sharing the same application domain and topic. One successful counter-example is the FFMpeg multimedia project, since several of its components are widely and consistently reused into other OSS projects. This paper documents the history of the libavcodec library of components from the FFMpeg project, which at present is reused in more than 140 OSS projects. Most of the recipients use it as a black-box component, although a number of OSS projects keep a copy of it in their repositories, and modify it as such. In both cases, we argue that libavcodec is a successful example of reusable OSS library of components.
Keywords: component-based software development; OSS components; Software reuse

System compatibility analysis of Eclipse and Netbeans based on bug data - Baik, Eilwoo; Devanbu, Premkar; Wang, Xinlei (Oscar) (Proceedings of the 8th working conference on Mining software repositories - MSR '11, 2011)
Eclipse and Netbeans are two top of the line Integrated Development Environments (IDEs) for Java development. Both of them provide support for a wide variety of development tasks and have a large user base. This paper provides an analysis and comparison for the compatibility and stability of Eclipse and Netbeans on the three most commonly used operating systems, Windows, Linux and Mac OS. Both IDEs are programmed in Java and use a Bugzilla issue tracker to track reported bugs and feature requests. We looked into the Bugzilla repository databases of these two IDEs, which contains the bug records and histories of these two IDEs. We used some basic data mining techniques to analyze some historical statistics of the bug data. Based on the analysis, we try to answer certain stability-comparison oriented questions in the paper, so that users can have a better idea which of these two IDEs is designed better to work on different platforms.
Keywords: bug tracking system; bugzilla; eclipse; ms challenge; netbeans; version history

A tale of two browsers - Davis, Ian; Godfrey, Michael W.; Baysal, Olga (Proceedings of the 8th working conference on Mining software repositories - MSR '11, 2011)
We explore the space of open source systems and their user communities by examining the development artifact histories of two popular web browsers -- Firefox and Chrome -- as well as usage data. By examining the data and addressing a number of research questions, two very different profiles emerge: Firefox, as the older and established system, with long product version cycles but short bug fix cycles, and a user base that is slow to adopt newer versions; and Chrome, as the new and fast evolving system, with short version cycles, longer bug fix cycles, and a user base that very quickly adopts new versions as they become available (due largely to Chrome's mandatory automatic updates).
Keywords: chrome; development history; Firefox; msr challenge

Teaching distributed software engineering with UCOSP: the undergraduate capstone open-source project - Stroulia, Eleni; Bauer, Ken; Craig, Michelle; Reid, Karen; Wilson, Greg (Proceedings of the 2011 Community Building Workshop on Collaborative Teaching of Globally Distributed Software Development, 2011)
Software engineering courses in computer-science departments are meant to prepare students for the practice of designing, developing, understanding and maintaining software in the real world. The effectiveness of these courses have potentially a tremendous impact on the software industry, since it is through these courses that students must learn the state-of-the-art process and the tools of their eventual "trade", so that they can bring this knowledge to their job and thus advance the actual state of practice. The value of "learning software engineering" through project-based courses has long been recognized by educators and practitioners alike. In this paper, we discuss our experience with a distributed project-based course, which infuses the students' learning experience with an increased degree of realism, which, we believe, further improves the quality of their learning and advances their readiness to join the profession.
Keywords: distributed; education; pedagogical; project-based courses; software engineering education

The Third Generation of OSS: A Three-Stage Evolution from Gift to Commerce-Economy - Yamakami, Toshihiko (Open Source Systems: Grounding Research (OSS 2011), 2011)
Linux is penetrating into mobile software as the basis for a mobile middleware platform. It is accelerating the increasing visibility of open source software (OSS) components in mobile middleware platforms. Considering the 10-million lines of code of OSS-based industrial platforms such as a mobile middleware platform, engagement in foundations is inevitable for large-scale packages of OSS for industrial solutions. The author discusses the driving factors toward a foundation-based OSS and the transition of the underlying economy types to analyze the transitions to the third-generation OSS.

To Fork or Not to Fork: Fork Motivations in SourceForge Projects - Nyman, Linus; Mikkonen, Tommi (Open Source Systems: Grounding Research (OSS 2011), 2011)
A project fork occurs when software developers take a copy of source code from one software package and use it to begin an independent development work that is maintained separately from its origin. Although forking in open source software does not require the permission of the original authors, the new version, nevertheless, competes for the attention of the same developers that have worked on the original version. The motivations developers have for performing forks are many, but in general they have received little attention. In this paper, we present the results of a study of forks performed in SourceForge (http://sourceforge.net/) and list the developers’ motivations for their actions. The main motivation, seen in close to half of the cases of forking, was content modification; either adding content to the original program or focusing the content to the needs of a specific segment of users. In a quarter of the cases the motivation was technical modification; either porting the program to new hardware or software, or improving the original.
Keywords: fork rate; sourceforge

Tool Assisted Analysis of Open Source Projects - Syeed, M.M. Mahbubul; Aaltonen, Timo; Hammouda, Imed; Systä, Tarja (International Journal of Open Source Software and Processes, 2011)
Open Source Software (OSS) is currently a widely adopted approach to developing and distributing software. OSS code adoption requires an understanding of the structure of the code base. For a deeper understanding of the maintenance, bug fixing and development activities, the structure of the developer community also needs to be understood, especially the relations between the code and community structures. This, in turn, is essential for the development and maintenance of software containing OSS code. This paper proposes a method and support tool for exploring the relations of the code base and community structures of OSS projects. The method and proposed tool, Binoculars, rely on generic and reusable query operations, formal definitions of which are given in the paper. The authors demonstrate the applicability of Binoculars with two examples. The authors analyze a well-known and active open source project, FFMpeg, and the open source version of the IaaS cloud computing project Eucalyptus.
Keywords: artifacts; tools

Towards a Unified Definition of Open Source Quality - Ruiz, Claudia; Robinson, William (Open Source Systems: Grounding Research (OSS 2011), 2011)
Software quality needs to be specified and evaluated in order to determine the success of a development project, but this is a challenge with Free/Libre Open Source Software (FLOSS) because of its permanently emergent state. This has not deterred the growth of the assumption that FLOSS is higher quality than traditionally developed software, despite of mixed research results. With this literature review, we found the reason for these mixed results is that that quality is being defined, measured, and evaluated differently. We report the most popular definitions, such as software structure measures, process measures, such as defect fixing, and maturity assessment models. The way researchers have built their samples has also contributed to the mixed results with different project properties being considered and ignored. Because FLOSS projects are evolving, their quality is too, and it must be measured using metrics that take into account its community’s commitment to quality rather than just its software structure. Challenges exist in defining what constitutes a defect or bug, and the role of modularity in affecting FLOSS quality.
Keywords: literature review; measurement; open source; quality; Software

Towards Improving OSS Products Selection – Matching Selectors and OSS Communities Perspectives - Ayala, Claudia; Cruzes, Daniela S.; Franch, Xavier; Conradi, Reidar (Open Source Systems: Grounding Research (OSS 2011), 2011)
Adopting third-party software is becoming an economical and strategic need for today organizations. A fundamental part of its successful adoption is the informed selection of products that best fit the organization needs. One of the main current problems hampering selection, specially of OSS products is the vast amount of unstructured, incomplete, evolvable and widespread information about products that highly increases the risks of taking a wrong decision. In this paper, we aim to inform and provide evidence to OSS communities that help them to envisage improvements on their information rendering strategies to satisfy industrial OSS selectors’ needs. Our results are from the matching between the informational needs of 23 OSS selectors from diverse software-intensive organizations, and the in-depth study of 9 OSS communities of different sizes and domains. The results evidenced specific areas of improvement that might help to enhance the industrial OSS selection practice.
Keywords: empirical study; information rendering strategy; open source software; selection

Towards understanding twitter use in software engineering: preliminary findings, ongoing challenges and future questions - Bougie, Gargi; Starke, Jamie; Storey, Margaret-Anne; Daniel M. German (Proceedings of the 2nd International Workshop on Web 2.0 for Software Engineering, 2011)
There has been some research conducted around the motivation for the use of Twitter and the value brought by micro-blogging tools to individuals and business environments. This paper builds on our understanding of how the phenomenon affects the population which birthed the technology: Software Engineers. We find that the Software Engineering community extensively leverages Twitter's capabilities for conversation and information sharing and that use of the tool is notably different between distinct Software Engineering groups. Our work exposes topics for future research and outlines some of the challenges in exploring this type of data.
Keywords: eclipse; linux; mxunit; social media; software development; twitter; web 2.0

Towards understanding twitter use in software engineering: preliminary findings, ongoing challenges and future questions - Bougie, Gargi; Starke, Jamie; Storey, Margaret-Anne; Daniel M. German (Proceedings of the 2nd International Workshop on Web 2.0 for Software Engineering, 2011)
There has been some research conducted around the motivation for the use of Twitter and the value brought by micro-blogging tools to individuals and business environments. This paper builds on our understanding of how the phenomenon affects the population which birthed the technology: Software Engineers. We find that the Software Engineering community extensively leverages Twitter's capabilities for conversation and information sharing and that use of the tool is notably different between distinct Software Engineering groups. Our work exposes topics for future research and outlines some of the challenges in exploring this type of data.
Keywords: eclipse; linux; mxunit; social media; software development; twitter; web 2.0

Understanding broadcast based peer review on open source software projects - Peter C. Rigby; Storey, Margaret-Anne (Proceedings of the 33rd International Conference on Software Engineering, 2011)
Software peer review has proven to be a successful technique in open source software (OSS) development. In contrast to industry, where reviews are typically assigned to specific individuals, changes are broadcast to hundreds of potentially interested stakeholders. Despite concerns that reviews may be ignored, or that discussions will deadlock because too many uninformed stakeholders are involved, we find that this approach works well in practice. In this paper, we describe an empirical study to investigate the mechanisms and behaviours that developers use to find code changes they are competent to review. We also explore how stakeholders interact with one another during the review process. We manually examine hundreds of reviews across five high profile OSS projects. Our findings provide insights into the simple, community-wide techniques that developers use to effectively manage large quantities of reviews. The themes that emerge from our study are enriched and validated by interviewing long-serving core developers.
Keywords: apache; case studies; email; freebsd; grounded theory; kde; linux; linux kernel; open source software; peer review; subversion

Validity Issues in the Use of Social Network Analysis with Digital Trace data - Howison, James; Andrea Wiggins; Kevin Crowston (Journal of the Association for Information Systems, 2011)
There is an exciting natural match between social network analysis methods and the growth of data sources produced by social interactions via information technologies, from online communities to corporate information systems. Information Systems researchers have not been slow to embrace this combination of method and data. Such systems increasingly provide "digital trace data" that provide new research opportunities. Yet digital trace data are substantively different from the survey and interview data for which network analysis measures and interpretations were originally developed. This paper examines ten validity issues associated with the combination of data digital trace data and social network analysis methods, with examples from the IS literature, to provide recommendations for improving the validity of research using this combination.
Keywords: information system; Online Communities; social network analysis; Virtuality

Virtual Health Information Infrastructures: A Scalable Regional Model - Seror, Ann (Open Source Systems: Grounding Research (OSS 2011), 2011)
Integrating research, education and evidence-based medical practice requires complex infrastructures and network linkages among these critical activities. This research examines communities of practice and open source software tools in development of scalable virtual infrastructures for the regional Virtual Health Library of the Latin American and Caribbean Health Sciences System (Bireme) and embedded national cases. Virtual infrastructures refer to an environment characterized by overlapping distribution networks accessible through Internet portals and websites designed to facilitate integrated use of available resources. Case analysis shows engagement of interdisciplinary communities of practice for scalable virtual infrastructure design. This research program considers theory and methods for study of transferability of the Latin American model to large health care systems in other cultures.
Keywords: Bireme; Communities Of Practice; culture; open source systems; virtual infrastructures

Visualizing collaboration and influence in the open-source software community - Marschner, Eli; Rosenfeld, Evan; Heer, Jeffrey; Heller, Brandon (Proceedings of the 8th working conference on Mining software repositories - MSR '11, 2011)
We apply visualization techniques to user profiles and repository metadata from the GitHub source code hosting service. Our motivation is to identify patterns within this development community that might otherwise remain obscured. Such patterns include the effect of geographic distance on developer relationships, social connectivity and influence among cities, and variation in project-specific contribution styles (e.g., centralized vs. distributed). Our analysis examines directed graphs in which nodes represent users' geographic locations and edges represent (a) follower relationships, (b) successive commits, or (c) contributions to the same project. We inspect this data using a set of visualization techniques: geo-scatter maps, small multiple displays, and matrix diagrams. Using these representations, and tools based on them, we develop hypotheses about the larger GitHub community that would be difficult to discern using traditional lists, tables, or descriptive statistics. These methods are not intended to provide conclusive answers; instead, they provide a way for researchers to explore the question space and communicate initial insights.
Keywords: COLLABORATION; data exploration; geography; geoscatter; github; graph; mapping; metadata; open source; social graph; user profiles; visualization

What kind of commons is free software? - Vieira, Miguel Said (Proceedings of the 6th Open Knowledge Conference (OKCon 2011), 2011)
This paper analyzes free software under the light of commons theories, and tries to answer whether it is a managed or open access commons. It briefly presents commons studies and its main concepts, as well as the discussion on immaterial commons, arguing that goods' intrinsic characteristics should not be viewed as absolute, but rather contextualized in social struggles. Then, it proposes a two-tier structure for analyzing free software as a commons, considering its dual nature as source and machine code. The two connected layers of the proposal - use and development - are characterized according to commons theory categories; Android and software forking are explored as examples. It concludes that the first layer resembles an open access commons, but with intensional boundaries, and that the second one resembles multiple managed commons. This disparity is associated with the category of nested enterprises and with the layers' relations to appropriation and production.
Keywords: commons; COMMUNITY; free software; governance

What topics do Firefox and Chrome contributors discuss? - Zagarese, Quirino; Distante, Damiano; Di Penta, Massimiliano; Bernardi, Mario Luca; Sementa, Carmine (Proceedings of the 8th working conference on Mining software repositories - MSR '11, 2011)
Firefox and Chrome are two very popular open source Web browsers, implemented in C/C++. This paper analyzes what topics were discussed in Firefox and Chrome bug reports over time. To this aim, we indexed the text contained in bug reports submitted each semester of the project history, and identified topics using Latent Dirichlet Allocation (LDA). Then, we investigated to what extent Firefox and Chrome developers/contributors discussed similar topics, either in different periods, or over the same period. Results indicate a non-negligible overlap of topics, mainly on issues related to page layouting, user interaction, and multimedia contents.
Keywords: bug reports; chrome; Firefox; LDA; msr challenge

When Cultures Clash: Participation in Open Source Communities and Its Implications For Organizational Commitment - Daniel, Sherae L.; Maruping, Likoebe M.; Cataldo, Marcelo; Herbsleb, James (ICIS 2011 Proceedings, 2011)
Software applications developed within the OSS community have enjoyed tremendous success and for-profit organizations are keen to tap into this significant pool of software development talent (Chesbrough 2003; Feller et al. 2008). Examples companies include Netscape, IBM and Google (Maccormack et al. 2006). These companies seek to benefit from the talent of a global and sometimes voluntary workforce by paying some employees to contribute to OSS projects (Raymond 1999, Shah 2006). This merging of open and traditional software development may cause developer stress based on conflicting OSS community and traditional software development norms. Specifically, developers must balance company intellectual property concerns with the reciprocal and community-based norms that drive OSS development (Stewart and Gosain 2006). When these values are not in sync, contributors that aim to abide by conflicting values may exhibit dysfunctional attitudes. Employee stress with respect to their role can be destructive to organizational outcomes (Maas and Matejka 2009; Aranya and Ferris 1984). This study develops an OSS context specific model that describes the relationship between clashing software development cultures and employee organizational commitment. We leverage the rich OSS literature and the research that focuses on organizational-professional conflict (OPC) to develop hypotheses linking clashing cultures and organizational commitment. These hypotheses are tested using a combination of archival data and a survey of 127 GNOME developers. The findings presented in this paper contribute to OSS literature and offer findings that will enable organizations to more successfully engage OSS communities.
Keywords: gnome

Adoption of open source software in software-intensive organizations – A systematic literature review - Hauge, Øyvind; Ayala, Claudia; Conradi, Reidar (Information and Software Technology, 2010)
Context Open source software (OSS) is changing the way organizations develop, acquire, use, and commercialize software. Objective This paper seeks to identify how organizations adopt OSS, classify the literature according to these ways of adopting OSS, and with a focus on software development evaluate the research on adoption of OSS in organizations. Method Based on the systematic literature review method we reviewed publications from 24 journals and seven conference and workshop proceedings, published between 1998 and 2008. From a population of 24,289 papers, we identified 112 papers that provide empirical evidence on how organizations actually adopt OSS. Results We show that adopting OSS involves more than simply using OSS products. We moreover provide a classification framework consisting of six distinctly different ways in which organizations adopt OSS. This framework is used to illustrate some of the opportunities and challenges organizations meet when approaching OSS, to show that OSS can be adopted successfully in different ways, and to organize and review existing research. We find that existing research on OSS adoption does not sufficiently describe the context of the organizations studied, and it fails to benefit fully from related research fields. While existing research covers a large number of topics, it contains very few closely related studies. To aid this situation, we offer directions for future research. Conclusion The implications of our findings are twofold. On the one hand, practitioners should embrace the many opportunities OSS offers, but consciously evaluate the consequences of adopting it in their own context. They may use our framework and the success stories provided by the literature in their own evaluations. On the other hand, researchers should align their work, and perform more empirical research on topics that are important to organizations. Our framework may be used to position this research and to describe the context of the organization they are studying.
Keywords: open source software; organizations; software development; Systematic literature review

An Analysis of the Adoption of Open Source Software by Local Public Administrations - Rentocchini, Francesco; Tartari, Dimitri (International Journal of Open Source Software and Processes, 2010)
The wide diffusion of open source software (OSS) is driving discussion among scholars on a set of issues, including its adoption by public administrations (PA). Previous works discussed a few factors that drive the decision to adopt OSS and did not address the potential benefits in terms of e-government that OSS may bring to PA. This paper fills these gaps. The analysis is based on the Emilia-Romagna region of Italy and studies the adoption of software (both proprietary and open source) by local PA. The results show there is increased adoption of OSS in several different domains of application, both servers and desktop clients. Among the motivations to adopt OSS, dependence on software suppliers is important. Its adoption also positively affects the variety and extent of interactivity of local public e-services.
Keywords: government

Analysis of virtual communities supporting OSS projects using social network analysis - Toral, S.L.; Martínez-Torres, M.R.; Barrero, F. (Information and Software Technology, 2010)
This paper analyses the behaviour of virtual communities for Open Source Software (OSS) projects. The development of OSS projects relies on virtual communities, which are built on relationships among members, being their final objective sharing knowledge and improving the underlying project. This study addresses the interactive collaboration in these kinds of communities applying social network analysis (SNA). In particular, SNA techniques will be used to identify those members playing a middle-man role among other community members. Results will illustrate the importance of this role to achieve successful virtual communities.
Keywords: arm; email; Knowledge brokers; linux; mailing list; open source software; social network analysis; virtual communities

Analyzing Leadership Dynamics in Distributed Group Communication - Kevin Crowston; Andrea Wiggins; Howison, James (2010 43rd Hawaii International Conference on System Sciences (HICSS 2010), 2010)
We apply social network analysis (SNA) to examine the dynamics of leadership in distributed groups, specifically Free/Libre Open Source Software development projects, and its relation to group performance. Based on prior work on leadership in distributed groups, we identify leaders with those who make the highest level of contribution to the group and assess the degree of leadership by measuring centralization of communications. We compare the dynamics of leadership in two FLOSS projects, one more and one less effective. We find that in both projects, centralization was higher in developer-oriented communications venues than in user-oriented venues, suggesting higher degrees of leadership in developer venues. However, we do not find a consistent relation between centralization and effectiveness. We suggest that SNA can instead be useful for identifying interesting periods in the history of the project, e.g., periods where the leadership of the project is in transition.
Keywords: core; DYNAMICS; email; email archives; fire; flossmole; gaim; leadership; mailing list; project success; social network analysis; srda

Assessment of issue handling efficiency - Luijten, Bart; Visser, Joost; Zaidman, Andy (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
We mined the issue database of GNOME to assess how issues are handled. How many issues are submitted and resolved? Does the backlog grow or decrease? How fast are issues resolved? Does issue resolution speed increase or decrease over time? In which subproject are issues handled most efficiently? To answer such questions, we apply several visualization and quantification instruments to the raw issue data. In particular, we aggregate issues into four risk categories, based on their resolution time. These categories are the basis both for visualizing and ranking, which are used in concert for issue database exploration.
Keywords: bug reports; bug tracking; classification; gnome; msr challenge; visualization

Atratividade de projetos de software livre: importância teórica e estratégias para administração - Santos Jr, Carlos Denner dos (Revista de Administração de Empresas, 2010)
Milhares de Projetos de Software Livre (PSL) foram e continuam sendo criados na Internet. Esse cenário aumenta as oportunidades de colaboração tanto quanto acirra a concorrência por usuários e contribuidores, que elevariam esses projetos a níveis superiores aos que seriam alcançados por seus fundadores sozinhos. E dado que o aprimoramento por meio de colaboração é o principal objetivo dos fundadores de PSL, a importância de entender e administrar a capacidade de atrair usuários e contribuidores fica estabelecida. Para auxiliar pesquisadores e fundadores nesse desafio, o conceito de atratividade é introduzido neste artigo, que desenvolve um ferramental teórico-gerencial sobre as causas, indicadores e consequências da atratividade, viabilizando sua administração estratégica.
Keywords: flossmole

Automated dependency resolution for open source software - Ossher, Joel; Bajracharya, Sushil; Lopes, Cristina (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
Opportunities for software reuse are plentiful, thanks in large part to the widespread adoption of open source processes and the availability of search engines for locating relevant artifacts. One challenge presented by open source software reuse is simply getting a newly downloaded artifact to build/run in the first place. The artifact itself likely reuses other artifacts, and so depends on their being located to function properly. While merely tedious in the individual case, this can cause serious difficulties for those seeking to study open source software. It is simply not feasible to manually resolve dependencies for thousands of projects, and many forms of analysis require declarative completeness. In this paper we present a method for automatically resolving dependencies for open source software. It works by cross-referencing a project's missing type information with a repository of candidate artifacts. We have implemented this method on top of the Sourcerer, an infrastructure for the large-scale indexing and analysis of open source code. The performance of our resolution algorithm was evaluated in two parts. First, for a small number of popular open source projects, we manually examined the artifacts suggested by our system to determine if they were appropriate. Second, we applied the algorithm to the 13,241 projects in the Sourcerer managed repository to evaluate the rate of resolution success. The results demonstrate the feasibility of this approach, as the algorithm located all of the required artifacts needed by 3,904 additional projects, increasing the percentage of declaratively complete projects in Sourcerer from 39% to 69%.
Keywords: dependencies; java; source code; sourcerer

Beyond replication: An example of the potential benefits of replicability in the mining of software repositories community - Gregorio Robles; Daniel M. German (1st Workshop on Replication in Empirical Software Engineering Research, 2010)
Keywords: literature review; msr; replication

Can development work describe itself? - Maalej, Walid; Happel, Hans-Jorg (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
Work descriptions are informal notes taken by developers to summarize work achieved in a particular session. Existing studies indicate that maintaining them is a distracting task, which costs a developer more than 30 min. a day. The goal of this research is to analyze the purposes of work descriptions, and find out if automated tools can assist developers in efficiently creating them. For this, we mine a large dataset of heterogeneous work descriptions from open source and commercial projects. We analyze the semantics of these documents and identify common information entities and granularity levels. Information on performed actions, concerned artifacts, references and new work, shows the work management purpose of work descriptions. Information on problems, rationale and experience shows their knowledge sharing purpose. We discuss how work description information, in particular information used for work management, can be generated by observing developers' interactions. Our findings have many implications for next generation software engineering tools.
Keywords: developer interactions; work descriptions

Clones: What is that smell? - Rahman, Foyzur; Christian Bird; Devanbu, Premkumar (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
Clones are generally considered bad programming practice in software engineering folklore. They are identified as a bad smell and a major contributor to project maintenance difficulties. Clones inherently cause code bloat, thus increasing project size and maintenance costs. In this work, we try to validate the conventional wisdom empirically to see whether cloning makes code more defect prone. This paper analyses relationship between cloning and defect proneness. We find that, first, the great majority of bugs are not significantly associated with clones. Second, we find that clones may be less defect prone than non-cloned code. Finally, we find little evidence that clones with more copies are actually more error prone. Our findings do not support the claim that clones are really a "bad smell". Perhaps we can clone, and breathe easy, at the same time.
Keywords: apache; bug fix revisions; bugs; clone; evolution; gimp; nautilus; scm; source code

Cloning and copying between GNOME projects - Krinke, Jens; Gold, Nicolas; Jia, Yue; Binkley, David (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
This paper presents an approach to automatically distinguish the copied clone from the original in a pair of clones. It matches the line-by-line version information of a clone to the pair's other clone. A case study on the GNOME Desktop Suite revealed a complex flow of reused code between the different subprojects. In particular, it showed that the majority of larger clones (with a minimal size of 28 lines or higher) exist between the subprojects and more than 60% of the clone pairs can be automatically separated into original and copy.
Keywords: clone; gnome; msr challenge; source code

Collaboration Practices and Affordances in Free/Open Source Software Development - Walt Scacchi (Collaborative Software Engineering, 2010)
This chapter examines collaborative work practices, development processes, project and community dynamics, and other socio-technical relationships in free and open source software development (FOSSD). It also describes what kinds of collaboration affordances facilitate collaborative work in FOSSD projects. It reviews a set of empirical studies of FOSSD that articulate different levels of analysis. Finally, there is discussion of limitations and constraints in understanding what collaboration practices and affordances arise in FOSSD studies and how they work, and then to emerging opportunities for future FOSSD studies.

A comparative exploration of FreeBSD bug lifetimes - Bougie, Gargi; Treude, Christoph; Daniel M. German; Storey, Margaret-Anne (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
In this paper, we explore the viability of mining the basic data provided in bug repositories to predict bug lifetimes. We follow the method of Lucas D. Panjer as described in his paper, Predicting Eclipse Bug Lifetimes. However, in place of Eclipse data, the FreeBSD bug repository is used. We compare the predictive accuracy of five different classification algorithms applied to the two data sets. In addition, we propose future work on whether there is a more informative way of classifying bugs than is considered by current bug tracking systems.
Keywords: bug reports; bug tracking; classification; eclipse; msr challenge; prediction

Creating and evolving developer documentation - Dagenais, Barthélémy; Robillard, Martin P. (Proceedings of the eighteenth ACM SIGSOFT international symposium, 2010)
Developer documentation helps developers learn frameworks and libraries. To better understand how documentation in open source projects is created and maintained, we performed a qualitative study in which we interviewed core contributors who wrote developer documentation and developers who read documentation. In addition, we studied the evolution of 19 documents by analyzing more than 1500 document revisions. We identified the decisions that contributors make, the factors influencing these decisions and the consequences for the project. Among many findings, we observed how working on the documentation could improve the code quality and how constant interaction with the projects' community positively impacted the documentation.

Data Mining User Activity in Free and Open Source Software (FOSS)/ Open Learning Management Systems - McGrath, Owen (International Journal of Open Source Software and Processes, 2010)
Free and Open Source Software (FOSS)/Open Educational Systems development projects abound in higher education today. Many universities worldwide have adopted open source software like ATutor and Moodle as an alternative to commercial or homegrown systems. The move to open source learning management systems entails many special considerations, including usage analysis facilities. The tracking of users and their activities poses major technical and analytical challenges within web-based systems. This paper examines how user activity tracking challenges are met with data mining techniques, particularly web usage mining methods, in four different open learning management systems: ATutor, LON-CAPA, Moodle, and Sakai. As examples of data mining technologies adapted within widely used systems, they represent important first steps for moving educational data mining outside the research laboratory. Moreover, as examples of different open source development contexts, exemplify the potential for programmatic integration of data mining technology processes in the future. As open systems mature in the use of educational data mining, they move closer to the long-sought goal of achieving more interactive, personalized, adaptive learning environments online on a broad scale.
Keywords: data mining; education; student

Developing a Dynamic and Responsive Online Learning Environment - Buchan, Janet (International Journal of Open Source Software and Processes, 2010)
Charles Stuart University adopted the open source software, Sakai, as the foundation for the university’s new, integrated Online Learning Environment. This study explores whether a pedagogical advantage exists in adopting such an open source learning management system. Research suggests that the community source approach to development of open source software has many inherent pedagogical advantages, but this paper examines whether this is due to the choice of open source software or simply having access to appropriate technology for learning and teaching in the 21st century. The author also addresses the challenges of the project management methodology and processes in the large-scale implementation of an open-source courseware management solution at the institutional level. Consequently, this study outlines strategies that an institution can use to harness the potential of a community source approach to software development to meet the institutional and individual user needs into the future.
Keywords: education; learning; sakai

Do stack traces help developers fix bugs? - Schroter, Adrian; Schröter, Adrian; Bettenburg, Nicolas; Premraj, Rahul (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
A widely shared belief in the software engineering community is that stack traces are much sought after by developers to support them in debugging. But limited empirical evidence is available to confirm the value of stack traces to developers. In this paper, we seek to provide such evidence by conducting an empirical study on the usage of stack traces by developers from the ECLIPSE project. Our results provide strong evidence to this effect and also throws light on some of the patterns in bug fixing using stack traces. We expect the findings of our study to further emphasize the importance of adding stack traces to bug reports and that in the future, software vendors will provide more support in their products to help general users make such information available when filing bug reports.
Keywords: bug fixing; bug report; debugging; eclipse; stack trace

Download Patterns and Releases in Open Source Software Projects: A Perfect Symbiosis? - Rossi, Bruno; Russo, Barbara; Succi, Giancarlo (Open Source Software: New Horizons, 2010)
Software usage by end-users is one of the factors used to evaluate the success of software projects. In the context of open source software, there is no single and non-controversial measure of usage, though. Still, one of the most used and readily available measure is data about projects downloads. Nevertheless, download counts and averages do not convey as much information as the patterns in the original downloads time series. In this research, we propose a method to increase the expressiveness of mere download rates by considering download patterns against software releases. We apply experimentally our method to the most downloaded projects of SourceForge's history crawled through the FLOSSMole repository. Findings show that projects with similar usage can have indeed different levels of sensitivity to releases, revealing different behaviors of users. Future research will develop further the pattern recognition approach to automatically categorize open source projects according to their download patterns.
Keywords: flossmole; oss2010; sourceforge

The Economic Case for Open Source Foundations - Dirk Riehle (Computer, 2010)
An open source foundation is a group of people and companies that has come together to jointly develop community open source software. Examples include the Apache Software Foundation, the Eclipse Foundation, and the Gnome Foundation. There are many reasons why software development firms join and support a foundation. One common economic motivation is to save costs in the development of the software by spreading them over the participating parties. However, this is just the beginning. Beyond sharing costs, participating firms can increase their revenue through the provision and increased sale of complementary products. Also, by establishing a successful open source platform, software firms can compete more effectively across technology stacks and thereby increase their addressable market. Not to be neglected, community open source software is a common good, creating increased general welfare and hence goodwill for the involved companies.

The evolution of ANT build systems - McIntosh, Shane; Adams, Bram; Hassan, Ahmed E. (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
Build systems are responsible for transforming static source code artifacts into executable software. While build systems play such a crucial role in software development and maintenance, they have been largely ignored by software evolution researchers. With a firm understanding of build system aging processes, project managers could allocate personnel and resources to build system maintenance tasks more effectively, reducing the build maintenance overhead on regular development activities. In this paper, we study the evolution of ANT build systems from two perspectives: (1) a static perspective, where we examine the build system specifications using software metrics adopted from the source code domain; and (2) a dynamic perspective where representative sample build runs are conducted and their output logs are analyzed. Case studies of four open source ANT build systems with a combined history of 152 releases show that not only do ANT build systems evolve, but also that they need to react in an agile manner to changes in the source code.
Keywords: ant; argouml; build; eclipse; jboss; maintenance; metrics; source code; tomcat

Exploring Complexity in Open Source Software: Evolutionary Patterns, Antecedents, and Outcomes - Darcy, David P.; Daniel, Sherae L.; Stewart, Katherine J. (2010 43rd Hawaii International Conference on System Sciences (HICSS 2010), 2010)
Software complexity is important to researchers and managers, yet much is unknown about how complexity evolves over the life of a software application and whether different dimensions of software complexity may exhibit similar or different evolutionary patterns. Using cross-sectional and longitudinal data on a sample of 108 open source projects, this research investigated how the complexity of open source project releases varied throughout the life of the project. Functional data analysis was applied to the release histories of the projects and recurring evolutionary patterns were derived. There were projects that saw little evolution, according to their measures of size and structural complexity. However, projects that displayed some evolution often differed on the pattern of evolution depending on whether size or structural complexity was examined. Factors that contribute to and result from the patterns of complexity were evaluated, and implications for research and practice are presented.
Keywords: complexity; evolution; fda; life cycle; sourceforge; srda

An extensive comparison of bug prediction approaches - D'Ambros, Marco; Lanza, Michele; Robbes, Romain (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
Reliably predicting software defects is one of software engineering's holy grails. Researchers have devised and implemented a plethora of bug prediction approaches varying in terms of accuracy, complexity and the input data they require. However, the absence of an established benchmark makes it hard, if not impossible, to compare approaches. We present a benchmark for defect prediction, in the form of a publicly available data set consisting of several software systems, and provide an extensive comparison of the explanative and predictive power of well-known bug prediction approaches, together with novel approaches we devised. Based on the results, we discuss the performance and stability of the approaches with respect to our benchmark and deduce a number of insights on bug prediction models.
Keywords: apache; bug reports; eclipse; famix; lucene; mylyn; prediction; scm

Extracting source code from e-mails - Bacchelli, Alberto; D'Ambros, Marco; Lanza, Michele (Proceedings of ICPC 2010 (18th IEEE International Conference on Program Comprehension), 2010)
E-mails, used by developers and system users to communicate over a broad range of topics, offer a valuable source of information. If archived, e-mails can be mined to support program comprehension activities and to provide views of a software system that are alternative and complementary to those offered by the source code. However, e-mails are written in natural language, and therefore contain noise that makes it difficult to retrieve the important data. Thus, before conducting an effective system analysis and extracting data for program comprehension, it is necessary to select the relevant messages, and to expose only the meaningful information. In this work we focus both on classifying e-mails that hold fragments of the source code of a system, and on extracting the source code pieces inside the e-mail. We devised and analyzed a number of lightweight techniques to accomplish these tasks. To assess the validity of our techniques, we manually inspected and annotated a statistically significant number of e-mails from five unrelated open source software systems written in Java. With such a benchmark in place, we measured the effectiveness of each technique in terms of precision and recall.
Keywords: argouml; email; freenet; jmeter; mailing lists; mina; natural language; openjpa; source code

Finding file clones in FreeBSD Ports Collection - Sasaki, Yusuke; Yamamoto, Tetsuo; Hayase, Yasuhiro; Inoue, Katsuro (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
In Open Source System (OSS) development, software components are often imported and reused; for this reason we might expect that files are copied in multiple projects (file clones). In this paper, we propose a file clone detection tool called FCFinder and show the analysis performed with it on the FreeBSD Ports Collection, a large OSS project collection. We found many file clones among similar or related projects, which are systematically introduced from base projects.
Keywords: clone; freebsd; msr challenge; source code

A Fistful of Dollars: Financial Rewards, Payment Norms, and Motivation Crowding in Open Source Software Development - Oliver Alexy; Martin Leitner (SSRN, 2010)
Existing literature on open source software (OSS) maintains that intrinsic motivation and extrinsic financial rewards have a unidimensionally positive effect on the motivation of individual developers. Based on self-determination theory, which underlies most of these studies, we challenge this assumption. We argue that the effect of payment on both intrinsic motivation and total motivation of OSS developers is far more complex. To illustrate our point, we introduce the concept of individuals’ norms about payment to the field of OSS. In doing so, we are able to show that payment norms moderate the effect of payment on intrinsic motivation and total motivation. Conducting a scenario experiment, we find that intrinsic motivation decreases for individuals with norms against payment. This effect becomes even stronger when analyzing for mediation effects. Total motivation is impacted positively by payment, but the effect turns insignificant for individuals with norms for payment. Our findings help explain the results of previous studies in which OSS developers did not seem to be affected by motivation crowding. They further contribute to the more general debate on how to manage individuals in the absence of formal contracts. From a practical perspective, we show that financial rewards may create a management dilemma for OSS project leaders.
Keywords: developers; experiment; financial; MOTIVATION

From Proprietary to Open Source: Building a Network of Trust - Sirkkala, Petri; Hammouda, Imed; Aaltonen, Timo (Second International Workshop on Building Sustainable Open Source Communities (OSCOMM 2010), 2010)
When a corporation is about to release a product as open source a large network of trust must be built and maintained. Open source and commercial domains have radically different aspects of trust. Still, trust is vital in products survival in both settings. This paper focuses on building cognitive, or rational, trust in both commercial and open source domains. We set the view angle so that trust can be approached via the various relationships between the stakeholders involved in the community building process. Towards this goal, the paper focuses on the first steps of the process by proposing a set of best practices.
Keywords: oss2010; osscomm; workshop

Helping to Bridge the Digital Divide with Free Software and Services - Caudill, Jason G. (International Journal of Open Source Software and Processes, 2010)
The growing importance of digital media in citizens’ participation in government is a major issue in obtaining government services, elections and campaigning in the 21st century. In order to participate in the consumption and creation of online media, citizens must have access to, and knowledge of, appropriate technology resources. There exists a gap between those who have access to technology and those who do not A gap commonly referred to as the digital divide. While there are many different aspects to the digital divide one of them is access to the software necessary to participate in digital media. A potential solution to the software component of the digital divide is the use of open source software and free online services. Implementing these solutions can play a part in narrowing the digital divide and producing better informed citizens more capable of participating in the modern electoral process.

Higher Education and FOSS for e-Learning - Williams van Rooij, Shahron (International Journal of Open Source Software and Processes, 2010)
This paper examines the paradox of FOSS adoption in U.S. institutions of higher education, where campus-wide deployment of FOSS for e-learning lags far behind adoption for technical infrastructure applications. Drawing on the fields of organizational management, information systems, and education, the author argues that the gap between FOSS advocacy and the enterprise-wide deployment of FOSS for e-learning is a consequence of the divergent perspectives of two organizational sub-cultures—the technologist and the academic—and the extent to which those sub-cultures are likely to embrace FOSS. The author recommends (a) collaborative needs analysis/assessment prior to a go/no go adoption decision, and (b) broad dissemination of total cost of ownership (TCO) data by institutions deploying FOSS for e-learning enterprise-wide. This discussion satisfies e-learning administrators and practitioners seeking research-based, cross-disciplinary evidence about the FOSS decision-making process and also assists educators seeking to expand student knowledge of e-learning technology options.
Keywords: education

Identifying licensing of jar archives using a code-search approach - Di Penta, Massimiliano; Daniel M. German; Antoniol, Giuliano (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
Free and open source software strongly promotes the reuse of source code. Some open source Java components/libraries are distributed as jar archives only containing the bytecode and some additional information. For whoever wanting to integrate this jar in her own project, it is important to determine the license(s) of the code from which the jar archive was produced, as this affects the way that such component can be used. This paper proposes an automatic approach to determine the license of jar archives, combining the use of a code-search engine with the automatic classification of licenses contained in textual flies enclosed in the jar. Results of an empirical study performed on 37 jars - from 17 different systems - indicate that this approach is able to successfully infer the jar licenses in over 95% of the cases, but that in many cases the license in textual flies may differ from the one of the classes contained in the jar.
Keywords: apache; bytecode; classification; eclipse; google code; jar; java; licenses; source code

The Impact of Person-Organization Fit on Turnover in Open Source Software Projects - Sharma, P.N.; Daniel, Sherae L.; Chung, Ting-Ting (Rachel) (ICIS 2010 Proceedings, 2010)
Participant turnover in open source software development is a critical problem. Using Schneider’s (1987) Attraction Selection and Attrition Framework and the notion of Person- Organization fit, we hypothesize about the relationship between a participant's fit with an open source project and turnover. Specifically we predict that value fit, needs-supplies fit and demandsabilities fit between a participant and a particular project will have a negative association with participant turnover and that the role of the participant in the project acts a moderator. An empirical study is designed to examine the hypotheses using a combination of survey and archival data. Since for-profit companies are increasingly leveraging open source software development, implications of our findings will be useful for project managers seeking to retain talented contributors in the absence of financial compensation.

Impact of Programming Language Fragmentation on Developer Productivity - Krein, Jonathan L.; MacLean, Alexander C.; Knutson, Charles D.; Delorey, Daniel P.; Eggett, Dennis L. (International Journal of Open Source Software and Processes, 2010)
Programmers often develop software in multiple languages. In an effort to study the effects of programming language fragmentation on productivity—and ultimately on a developer’s problem-solving abilities—the authors present a metric, language entropy, for characterizing the distribution of a developer’s programming efforts across multiple programming languages. This paper presents an observational study examining the project contributions of a random sample of 500 SourceForge developers. Using a random coefficients model, the authors find a statistically (alpha level of 0.001) and practically significant correlation between language entropy and the size of monthly project contributions. Results indicate that programming language fragmentation is negatively related to the total amount of code contributed by developers within SourceForge, an open source software (OSS) community.
Keywords: commits; entropy; language entropy; programming languages; sourceforge; srda

The Importance of Social Network Structure in the Open Source Software Developer Community - Matthew Van Antwerp; Madey, Greg (2010 43rd Hawaii International Conference on System Sciences, 2010)
This paper outlines the motivations and methods for analyzing the developer network of open source software (OSS) projects. Previous work done by Hinds [5] suggested social network structure was instrumental towards the success of an OSS project, as measured by activity and output. The follow-up paper by Hinds [4] discovered that his hypotheses, based on social network theory and previous research on the importance of subgroup connectedness, were vastly different than the results of his study of over 100 successful OSS projects. He concluded that the social network structure had no significant effect on project success. We outline how his approach disregarded potentially important factors and through a new study evaluate the role of the OSS developer network as it pertains to long-term project popularity. We also present an initial investigation into the adequacy of using the SourceForge activity percentile as a long-term success metric. In contrast with Hinds, we show that previously existing developer-developer ties are an indicator of past and future project popularity.
Keywords: developers; popularity; project success; social network analysis; sourceforge; srda

Investigating the Acquisition of Software Systems that Rely on Open Architecture and Open Source Software - Walt Scacchi; Alspaugh, Thomas; Hazeline U. Asuncion (Naval Postgraduate School Acquisition Research Program, 2010)
In 2007-08, we began an investigation of problems, issues, and opportunities that arise during the acquisition of software systems that rely on open architectures and open source software. The current effort funded for 2009 seeks to continue and build on the results in this area, while refining its focus to center on the essential constraints and tradeoffs we have identified for software-intensive systems with open architecture (OA) and continuously evolving open source software (OSS) elements. The U.S. Air Force, Army, and Navy have all committed to an open technology development strategy that encourages the acquisition of software systems whose requirements include the development or composition of an OA for such systems, and the use of OSS systems, components, or development processes when appropriate. Our goal is to further develop and document foundations for emerging policy and guidance for acquiring software systems that require OA and that incorporate OSS elements. This report documents and describes the findings and results that we have produced as a result of our research into the area of the acquisition of software systems that rely on OA and OSS. In particular, it includes four research papers that have been refereed, reviewed, presented, and published in national and international research conferences, symposia, and workshops.

Investigating the Geography of Open Source Software through Github - Yuri Takhteyev; Andrew Hilts (2010)
The paper presents an empirical study of the geography of open source software development that looks at Github, a popular project hosting website. We show that developers are highly clustered and concentrated primarily in North America and Western and Northern Europe, though a substantial minority is present in other regions. Code contributions and attention show a strong local bias. Users in North America account for a larger share of received contributions than of contributions made. They also receive a disproportionate amount of attention.

Learning in Open Source Software (OSS) Development: How Developer Interactions in Culturally Diverse Projects Impact the Acquisition of Collaboration and Learning Skills - Diamant, I.; Daniel, S.L. (International Conference on Information Systems, 2010)
Participants in an OSS/FLOSS development project often span national and organizational boundaries, as developers from different countries and corporations join the project. A project team’s national and organizational culture creates opportunities for learning from others, but may also lead to conflict and inhibit learning. This research examines developers’ learning in an OSS project, and the cultural context in which learning takes place. We focus on single- and doubleloop learning and examine the impact of the team’s national and organizational culture on a developer’s learning. Archival and survey data are collected from two large-scale Sourceforge projects. This research can contribute to the OSS literature by examining the impact of team interactions on developers’ learning. Practically, administrators and managers stand to gain insight into the learning benefits of participation in OSS projects, and thus better assess their value as a training ground for global software development.
Keywords: sourceforge

'Letting go of Control' to Embrace Open Source: Implications for Company and Community - Maha Shaikh; Cornford, Tony (2010 43rd Hawaii International Conference on System Sciences (HICSS 2010), 2010)
It is increasingly understood across the information technology and services sector that engagement with the open source software model can serve as a means for firms to capture intellectual energy, learn about productive software processes, access relevant technical skills, identify and recruit staff, as well as obtain valuable resources including code. This paper reports a study undertaken within two large global IT companies that have been actively involved with open source for more than ten years. The study involved over 30 semi-structured interviews with employees of the companies drawn from top, middle, and lower level management, and included active and experienced developer as well as open source community members. Our findings indicate how these companies have adapted their day-to-day management practices to take into account the need for flexibility and freedom expected by open source communities. This paper focuses on how they 'let go of control' and what the implications of this are for both companies and the communities involved. Our data reveals a number of themes and in this paper we focus on three principal ones; issues of requirements, total cost of adoption, and alignment of open source engagement with long term company strategy.
Keywords: adoption; companies; interviews; organizations

Linking e-mails and source code artifacts - Bacchelli, Alberto; Lanza, Michele; Robbes, Romain (Proceedings of the 32nd ACM/IEEE International Conference on Software Engineering - ICSE '10, 2010)
E-mails concerning the development issues of a system constitute an important source of information about high-level design decisions, low-level implementation concerns, and the social structure of developers. Establishing links between e-mails and the software artifacts they discuss is a non-trivial problem, due to the inherently informal nature of human communication. Different approaches can be brought into play to tackle this traceability issue, but the question of how they can be evaluated remains unaddressed, as there is no recognized benchmark against which they can be compared. In this article we present such a benchmark, which we created through the manual inspection of a statistically significant number of e-mails pertaining to six unrelated software systems. We then use our benchmark to measure the effectiveness of a number of approaches, ranging from lightweight approaches based on regular expressions to full-fledged information retrieval approaches.

Linkster: Enabling Efficient Manual Mining - Christian Bird; Adrian Bachman; Rahman, Foyzur; Bernstein, Abraham (Demonstration Track, Proceedings of the 17th SIGSOFT Symposium on Foundations of Software Engineering, 2010)
While many uses of mined software engineering data are automatic in nature, some techniques and studies either require, or can be improved, by manual methods. Unfortunately, manually inspecting, analyzing, and annotating mined data can be difficult and tedious, especially when information from multiple sources must be integrated. Oddly, while there are numerous tools and frameworks for automatically mining and analyzing data, there is a dearth of tools which facilitate manual methods. To fill this void, we have developed LINKSTER, a tool which integrates data from bug databases, source code repositories, and mailing list archives to allow manual inspection and annotation. LINKSTER has already been used successfully by an OSS project lead to obtain data for one empirical study.
Keywords: artifacts; bug; bug tracking; data mining; email; mailing lists; open source; source code

A Longitudinal Study on Collaboration Networks and Decision to Participate in a FLOSS Community - Guido Conaldi; Tonellato, Marco (5th Workshop on Public Data about Software Development (WoPDaSD 2010), 2010)
In this paper we conjecture that individual decisions of FLOSS (Free/Libre Open Source Software) developers to take on a task are influenced by network relations generated by collaboration among project members. In order to explore our conjecture we collected data on a FLOSS project team consisting of 227 developers committed since 2002 to the development of a web browser. We reconstructed 2-mode co- collaboration networks (software developer by bug) in which a tie represents an action taken by a developer in order to solve a specific bug. Co-collaboration networks were collected at five points in time during a six-month development cycle of the software. We report and discuss results of longitudinal actor-based modeling that we specify to test for the influence of local network structures on developer’s decision to take action on a specific bug. The study controls for bug-specific and developer-specific characteristics that may also affect developers’ decisions exogenously. We also control for priority and severity levels assigned by the team to bugs in an attempt to manage voluntary contribution.
Keywords: bicho; bug fixing; bug reports; bugzilla; COLLABORATION; developers; epiphany; flossmetrics; gnome; social network analysis

Lurking? Cyclopaths? A Quantitative Lifecyle Analysis of User Behavior in a Geowiki - Panciera, K.; Priedhorsky, R.; Erickson, T.; Terveen, L. (ACM Conference on Computer-Human Interaction (CHI), 2010)
Keywords: content,; geographic; geowiki,; information,; lurking; open; volunteer; volunteered; Wiki,; work,

Mining security changes in FreeBSD - Mauczka, Andreas; Schanes, Christian; Fankhauser, Florian; Bernhart, Mario; Grechenig, Thomas (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
Current research on historical project data is rarely touching on the subject of security related information. Learning how security is treated in projects and which parts of a software are historically security relevant or prone to security changes can enhance the security strategy of a software project. We present a mining methodology for security related changes by modifying an existing method of software repository analysis. We use the gathered security changes to find out more about the nature of security in the FreeBSD project and we try to establish a link between the identified security changes and a tracker for security issues (security advisories). We give insights how security is presented in the FreeBSD project and show how the mined data and known security problems are connected.
Keywords: freebsd; msr challenge; security

Mining subclassing directives to improve framework reuse - Bruch, Marcel; Mezini, Mira; Monperrus, Martin (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
To help developers in using frameworks, good documentation is crucial. However, it is a challenge to create high quality documentation especially of hotspots in white-box frameworks. This paper presents an approach to documentation of object-oriented white-box frameworks which mines from client code four different kinds of documentation items, which we call subclassing directives. A case study on the Eclipse JFace user-interface framework shows that the approach can improve the state of API documentation w.r.t. subclassing directives.
Keywords: api; documentation; eclipse; frameworks; jface; source code

On the Need for OSS Patch Contribution Tools - Bhuricha Deen Sethanandha; Bart Massey; William Jones (Second International Workshop on Building Sustainable Open Source Communities (OSCOMM 2010), 2010)
Open Source Software (OSS) projects and systems have become significant parts of the software economy. The sustainability of an OSS project depends largely on community contributions. The patch contribution process is important to OSS projects. Nevertheless, there are several issues negatively impacting patch contribution in mature OSS projects. These issues can be addressed by improving tools to support the patch contribution process.
Keywords: apache; kanban; patch; patch acceptance; patches

The onion has cancer: some social network analysis visualizations of open source project communication - Oezbek, Christopher; Prechelt, Lutz; Thiel, Florian (Proceedings of the 3rd International Workshop on Emerging Trends in Free/Libre/Open Source Software Research and Development (FLOSS '10), 2010)
Background: People contribute to OSS projects in wildly different degrees, from reporting a single defect once and never coming back to spending many hours each workday on the project over several years - or anything in between. It is a common conception that these degrees of participation sort the participants into a number of similar groups which are layered like the peels of an onion: The onion model. Objective: We check whether this model of gradually different degrees of participation is valid with respect to the participation in OSS project mailing-list traffic. Methods: We perform social network analysis based on replies to mailing-list messages and use visualization to check the nature of three different groups of participants. Results: There appears to be a discontinuity with respect to core members: The degree to which very active core members (as opposed to less active co-developers) react to e-mails of senders from the project's periphery is significantly higher than would be expected from their level of activity in general. Limitations: The effect might be an artifact of the assumption that each mailing-list message can be treated the same. Conclusions: We conclude that core member status may be qualitatively (rather than just quantitatively) different and the transition of individual mailing-list participants towards ever higher participation is qualitatively discontinuous.
Keywords: argouml; Bochs; bugzilla; communication structure; Flyspray; gEDA; Grub; MonetDB; open source process; request tracker; Rox; social network analysis; Xfce

On Open and Collaborative Software Development in the DoD - Hissam, S. A.; Weinstock, C.; Bass, L. (Seventh Annual Acquisition Research Symposium, NPS Proceedings -, 2010)
The US Department of Defense (specifically, but not limited to, the DoD CIO's Clarifying Guidance Regarding Open Source Software, DISA's launch of Forge.mil and OSD's Open Technology Development Roadmap Plan) has called for increased use of open source software and the adoption of best practices from the free/open source software (F/OSS) community to foster greater reuse and innovation between programs in the DoD. In our paper, we examine some key aspects of open and collaborative software development inspired by the success of the F/OSS movement as it might manifest itself within the US DoD. This examination is made from two perspectives: the reuse potential among DoD programs sharing software and the incentives, strategies and policies that will be required to foster a culture of collaboration needed to achieve the benefits indicative of F/OSS. Our conclusion is that to achieve predictable and expected reuse, not only are technical infrastructures needed, but also a shift to the business practices in the software development and delivery pattern seen in the traditional acquisition lifecycle is needed. Thus, there is potential to overcome the challenges discussed within this paper to engender a culture of openness and community collaboration to support the DoD mission.
Keywords: collaborative development; open source software; reuse; software engineering

Open Educational Resources in E-Learning - Rejas-Muslera, Ricardo J.; García-Tejedor, Alvaro J.; Rodriguez, Olga Peñalba (International Journal of Open Source Software and Processes, 2010)
According to Dr. B.R. Ambedkar's definition (Deshpande & Mugridge, 1994), Open Educational Resources (OER) are based on the philosophical view of knowledge as a collective, social product. In the last years the relevance of OER has been widely acknowledged and a high magnitude impact is to be expected for OER in the near future (Atkins et al, 2007), (Wiley & Gurrell, 2009), especially as a masterpiece in e-learning development. The aim of this chapter is to present an overview of OER in e-learning, focused on two fundamental aspects: (i) technical issues, mainly standards, and (ii) socio-economic and legal questions. This way the chapter deals with the most relevant issues in this matter: Which is the OER's role in education, especially for e-learning performance? Which are the technical resources and current standards needed for them? Which socio-economics and legal aspects influence the diffusion and use of OER?

Open for Social - Laffey, James; Schmidt, Matthew; Amelung, Christopher (International Journal of Open Source Software and Processes, 2010)
Online learning in K-12 and higher education has been growing rapidly, and open source software has the potential to improve the quality of e-learning. This paper describes how FOSS enables turning e-learning from a potentially restrictive framing of the education experience to an emergent and social experience. The authors identify several key elements of the FOSS model that position open source initiatives to contribute to the emergent and social nature of experience in e-learning. The authors also describe several challenges to developing FOSS in a community of educators for e-learning. These elements and challenges are illustrated in a brief case report about the development of an open source software system called Context-aware Activity Notification System (CANS). CANS (http://cansaware.com) is a notification system that integrates with collaborative work and learning systems and is designed around the importance of awareness of user activity, a user's social context and personal notification preferences.
Keywords: education

Open Scientific Entrepreneurship - von Kortzfleisch, Harald; Schaarschmidt, Mario; Magin, Philipp (International Journal of Open Source Software and Processes, 2010)
The objective of this article is to conceptually transfer the concept of open source software (OSS) development to scientific entrepreneurship and to hypothetically discuss the support potentials of this rather new development philosophy for what we than call open scientific entrepreneurship. Therefore, at first the authors will go into conceptual details of scientific entrepreneurship and than of OSS development. Following, the main thrust of the article presents open scientific entrepreneurship from two points of origin: first of all, OSS development as a specific form of scientific e-entrepreneurship and further on potential benefits of opening “traditional” scientific entrepreneurship up by looking at specific action fields. These action fields are theoretically based on the process and competence perspective of scientific entrepreneurship. Finally, the general benefits as well as downsides of the concept of openness are discussed on a generic level. It becomes obvious that there is need for balancing the tensions between an open and closed design pattern for scientific entrepreneurship with a general emphasis on the open design perspective.

Open Source Adoption Index - Saini, Sanjeev K.; Krishnan, C. N.; Rajaram, L. N. (International Journal of Open Source Software and Processes, 2010)
This paper reports the preliminary results of a study conducted to assess and quantify the adoption of Free/Open Source Software (FOSS) by organisations and enterprises. While almost all organisations use FOSS in some form today, there is a wide variation in the manner and extent to which they do so, and presently no quantitative measure exists that can capture the true picture. The present work has built a model with two sets of parameters that, when fed with relevant data about an organisation, generates a single number, the FOSS Adoption Index (FAI), for that organisation. The index is so defined that the higher its value for an organisation, the greater is the extent of FOSS adoption in that organisation. Beyond the single measure FAI that gives a coarse assessment, the model also allows drilling down to finer levels of granularity that provides deeper insights into the status and role of FOSS within a given organisation. Primary data collected for two classes of organisations through questionnaire based surveys and interviews have been used to demonstrate the working of the model as well as its potential usefulness for real world situations.

Open Source Software Developer and Project Networks - Madey, G.; van Antwerp, M. (IFIP Advances in Information and Communication TechnologyOpen Source Software: New Horizons, 2010)
This paper outlines complex network concepts and how social networks are built from Open Source Software (OSS) data. We present an initial study of the social networks of three different OSS forges, BerliOS Developer, GNU Savannah, and SourceForge. Much research has been done on snapshot or conflated views of these networks, especially SourceForge, due to the size of the SourceForge community. The degree distribution, connectedness, centrality, and scale-free nature of SourceForge has been presented for the network at particular points in time. However, very little research has been done on how the network grows, how connections were made, especially during its infancy, and how these metrics evolve over time.
Keywords: berlios; savannah; sourceforge

Open Source Software Systems - Lenin, R. B.; Ramaswamy, S.; Yu, Liguo; Govindan, R. B. (International Journal of Open Source Software and Processes, 2010)
Complex software systems and the huge amounts of data they produce are becoming an integral part of our organizations. We are also becoming increasingly dependent on high quality software products in our everyday lives. These systems ‘evolve’ as we identify and correct existing defects, provide new functionalities, or increase their nonfunctional qualities - such as security, maintainability, performance, etc. Simultaneously, more software development projects are distributed over multiple locations (often globally) and are often several millions of dollars in development costs. Consequently, as the Internet continually eliminates geographic boundaries, the concept of doing business within a single country has given way to companies focusing on competing in an international marketplace. The digitalization of work and the reorganization of work processes across many organizations have resulted in routine and/or commodity components being outsourced.

OSS developers context-specific Preferred Representational systems: A initial Neurolinguistic text analysis of the Apache mailing list - Junior, Methanias Colaco; Mendonca, Manoel; Farias, Mario; Henrique, Paulo (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
Open Source Software (OSS) mailing lists are used by developers to discuss software engineering tasks performed in the project. In the last years, researchers have been conducting mailing lists linguistic analyses for understanding the intricacies of OSS development. An unpublished approach for that is to use NeuroLinguistic Theory (NT). NT postulates the use of a Preferred Representational cognitive System (PRS) in specific contexts. This means that different resources and cognitive channels are used by developers in order to understand software, but what types of representational systems are the preferred by software engineers? This paper introduces a psychometrically-based neuro-linguistic analysis tool to classify developers, and presents early results of an experiment to assess the PRS of four top developers against a baseline of the Apache server mailing list.
Keywords: apache; email; email archives; mailing lists; neurolinguistics

Paying attention to each other in visible work communities: Modeling bursty systems of multiple activity streams - Olson, Jamie F; Howison, James; Carley, Kathleen (SocialCom/PASSAT(2010), 2010)
Online work projects, from open source to wikipedia, have emerged as an important phenomenon. These communities offer exciting opportunities to investigate social processes because they leave traces of their activity over time. Unlike traditional work teams, the participants in these communities are widely dispersed and work without centralized management. The question arises, then, as to the extent to which these are in fact communities: is the group simply the sum of the individuals that make it up, or does the group function as a social unit? We explore this question in the temporal domain. We argue that the rapid visibility of others’ work afforded by the information systems used by these projects reaches out and attracts the attention of others who are peripherally aware of the group’s online space, prompting them to begin or intensify their participation, binding separate individual streams of activity into a social entity. Previous work has suggested that for certain types of bursty social behavior (e.g. email), the frequency of the behavior is not homogeneously distributed but rather can be divided into two generative mechanisms: active sessions and passive background participation. We extend this work for the case of multiple conditionally independent streams of behavior, where each stream is generated by these two generative mechanisms. Our model can characterized by a double-chain hidden Markov model, allowing efficient inference using expectation-maximization. We apply this model to visible work communities by modeling each participant as a single stream of behavior, assessing transition probabilities between active sessions of different participants. This allows us to examine the extent to which the various members of the community are influenced by the active participation of others. Our results indicate that an active session by a participant at least triples the likelihood of another participant beginning an active session.

Perspectives on bugs in the Debian bug tracking system - Davies, Julius; Hanyu Zhang; Nussbaum, Lucas; Daniel M. German (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
Bugs in Debian differ from regular software bugs. They are usually associated with packages, instead of software modules. They are caused and fixed by source package uploads instead of code commits. The majority are reported by individuals who appear in the bug database once, and only once. There also exists a small group of bug reporters with over 1,000 bug reports each to their name. We also explore our idea that a high bug-frequency for an individual package might be an indicator of popularity instead of poor quality.
Keywords: bug reports; debian; msr challenge; popularity

Predicting the severity of a reported bug - Lamkanfi, Ahmed; Demeyer, Serge; Giger, Emanuel; Goethals, Bart (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
The severity of a reported bug is a critical factor in deciding how soon it needs to be fixed. Unfortunately, while clear guidelines exist on how to assign the severity of a bug, it remains an inherent manual process left to the person reporting the bug. In this paper we investigate whether we can accurately predict the severity of a reported bug by analyzing its textual description using text mining algorithms. Based on three cases drawn from the open-source community (Mozilla, Eclipse and GNOME), we conclude that given a training set of sufficient size (approximately 500 reports per severity), it is possible to predict the severity with a reasonable accuracy (both precision and recall vary between 0.65-0.75 with Mozilla and Eclipse; 0.70-0.85 in the case of GNOME).
Keywords: bug reports; eclipse; gnome; mozilla; severity; text mining

Proposed Application of Data Mining Techniques for Clustering Software Projects - Rezende, Henrique Ribiero; Esmin, Ahmed Ali Abdalla (INFOCOMP Special Edition, 2010)
Software projects always generate a lot of data, ranging from informal documentation to a database with thousands of lines of code. This information extracted from software projects takes even greater when it comes to OSS (Open Source Software). Such data may include source code base, historical change in the software, bug reports, mailing lists, among others. Using data mining techniques, we can extract valuable knowledge of this set of in formation, thus providing improvements throughout the process of software development. The results can be used to improve the quality of software, or even to manage the project in order to obtain maximum efficiency. This article proposes the application of data mining techniques to cluster software projects, cites the advantages that can be obtained with these techniques, and illustrates the application of data mining in a Open Source Software database
Keywords: flossmole

Reclassifying Success and Tragedy in FLOSS Projects - Andrea Wiggins; Kevin Crowston (Proceedings of the International Conference on Open Source Systems (OSS), 2010)
This paper presents the results of a replication of English & Schweik’s 2007 paper classifying FLOSS projects according to their stage of growth and indicators of success. We recreated the analysis using a comparable data set from 2006, with one additional point in time. We also expanded upon the original results by applying different criteria for evaluating the rate of new software releases for sustainability of project activity. We discuss the points of convergence and divergence from the original work from these extensions of the classification, and their implications for studying FLOSS development using archival data. The paper contributes new analysis of operationalizing success in FLOSS projects, with discussion of implications of the findings.
Keywords: FLOSS

Replaying IDE interactions to evaluate and improve change prediction approaches - Robbes, Romain; Pollet, Damien; Lanza, Michele (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
Change prediction helps developers by recommending program entities that will have to be changed alongside the entities currently being changed. To evaluate their accuracy, current change prediction approaches use data from versioning systems such as CVS or SVN. These data sources provide a coarse-grained view of the development history that flattens the sequence of changes in a single commit. They are thus not a valid basis for evaluation in the case of development-style prediction, where the order of the predictions has to match the order of the changes a developer makes. We propose a benchmark for the evaluation of change prediction approaches based on fine-grained change data recorded from IDE usage. Moreover, the change prediction approaches themselves can use the more accurate data to fine-tune their prediction. We present an evaluation procedure and use it on several change prediction approaches, both novel and from the literature, and report on the results.
Keywords: cbse; change based software evolution; change prediction; changes; commit; cvs; development history; eclipseeye; ide; mylyn; spyware; svn

Replicating MSR: A study of the potential replicability of papers published in the Mining Software Repositories proceedings - Gregorio Robles (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
This paper is the result of reviewing all papers published in the proceedings of the former International Workshop on Mining Software Repositories (MSR) (2004-2006) and now Working Conference on MSR (2007-2009). We have analyzed the papers that contained any experimental analysis of software projects for their potentiality of being replicated. In this regard, three main issues have been addressed: i) the public availability of the data used as case study, ii) the public availability of the processed dataset used by researchers and iii) the public availability of the tools and scripts. A total number of 171 papers have been analyzed from the six workshops/working conferences up to date. Results show that MSR authors use in general publicly available data sources, mainly from free software repositories, but that the amount of publicly available processed datasets is very low. Regarding tools and scripts, for a majority of papers we have not been able to find any tool, even for papers where the authors explicitly state that they have built one. Lessons learned from the experience of reviewing the whole MSR literature and some potential solutions to lower the barriers of replicability are finally presented and discussed.
Keywords: data; literature review; msr; replication

Repositories with Public Data about Software Development - Jesus M. Gonzalez-Barahona; Izquierdo-Cortazar, Daniel; Squire, Megan (International Journal of Open Source Software and Processes, 2010)
Empirical research on software development based on data obtained from project repositories and code forges is increasingly gaining attention in the software engineering research community. The studies in this area typically start by retrieving or monitoring some subset of data found in the repository or forge, and this data is later analyzed to find interesting patterns. However, retrieving information from these locations can be a challenging task. Meta-repositories providing public information about software development are useful tools that can simplify and streamline the research process. Public data repositories that collect and clean the data from other project repositories or code forges can help ensure that research studies are based on good quality data. This paper provides some insight as to how these meta-repositories (sometimes called a “repository of repositories”, RoR) of data about open source projects should be used to help researchers. This paper describes in detail two of the most widely used collections of data about software development: FLOSSmole and FLOSSMetrics.

Responsiveness as a measure for assessing the health of OSS ecosystems - Gamalielsson, Jonas; Lundell, Björn; Lings, Brian (Second International Workshop on Building Sustainable Open Source Communities (OSCOMM 2010), 2010)
The health of an Open Source ecosystem is an important decision factor when considering the adoption of Open Source software or when monitoring a seeded Open Source project. In this paper we introduce responsiveness as a qualitative measure of the quality of replies within mailing lists, which can be used for assessing ecosystem health. We consider one specific metric of responsiveness in this paper, and that is the response time of follow-up messages in mailing lists. We also describe a way for characterising the nature of communication in messages with short and long response times. The approach is tested in the context of the Nagios project, and we particularly focus on the responsiveness for contributors acting in their professional roles as core developers. Our contribution is a step towards a deeper understanding of voluntary support provided in mailing lists of OSS projects.
Keywords: email; email archives; gmane; mailing lists; nagios; response time; sourceforge

Second International Workshop on Building Sustainable Open Source Communities (OSCOMM 2010) - Hammouda, Imed; Aaltonen, Timo; Capiluppi, Andrea (Second International Workshop on Building Sustainable Open Source Communities (OSCOMM 2010), 2010)
The Second International Workshop on Building Sustainable Open Source Communities (OSCOMM 2010) aims at building a commu- nity of researchers and practitioners to share experiences and discuss chal- lenges involved in building and maintaining open source communities. De- tailed information regarding the workshop is available at http://tutopen.cs.tut.fi/oscomm10/.
Keywords: oscomm; oscomm2010; oss2010; workshop

Should I contribute to this discussion? - Ibrahim, Walid M; Bettenburg, Nicolas; Shihab, Emad; Adams, Bram; Hassan, Ahmed E. (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
Development mailing lists play a central role in facilitating communication in open source projects. Since these lists frequently host design and project discussions, knowledgeable contribution to these discussion threads is essential to avoid mis-communication that might slow-down the progress of a project. However, given the sheer volume of emails on these lists, it is easy to miss important discussions. To find out how developers are able to deal with mailing list discussions, we study the main factors that encourage developers to contribute to the development mailing lists. We develop personalized models to automatically identify discussion threads that a developer would contribute to based on his previous contribution behavior. Case studies on development mailing lists of three open source projects (Apache, PostgreSQL and Python) show that the average accuracy of our models is 89-85% and that the models vary significantly between different developers.
Keywords: apache; contributions; developers; email; email archives; mailing lists; postgresql; python

The small-world effect: The influence of macro-level properties of developer collaboration networks on open-source project success - Param Vir Singh (ACM Trans. Softw. Eng. Methodol., 2010)
In this study we investigate the impact of community-level networks—relationships that exist among developers in an OSS community—on the productivity of member developers. Specifically, we argue that OSS community networks characterized by small-world properties would positively influence the productivity of the member developers by providing them with speedy and reliable access to more quantity and variety of information and knowledge resources. Specific hypotheses are developed and tested using longitudinal data on a large panel of 4,279 projects from 15 different OSS communities hosted at Sourceforge. Our results suggest that significant variation exists in small-world properties of OSS communities at Sourceforge. After accounting for project, foundry, and time-specific observed and unobserved effects, we found a statistically significant relationship between small-world properties of a community and the technical and commercial success of the software produced by its members. In contrast to the findings of prior research, we also found the lack of a significant relationship between closeness and betweenness centralities of the project teams and their success. These results were robust to a number of controls and model specifications.
Keywords: collaborative software development; online community; open source software development; productivity; small world networks; social networks; sourceforge; team formation

The Sociability of Free Software: A GNU Look at Free Software Identified Businesses as Social Entrepreneurships - Barcomb, Ann (Maastricht University, 2010)
This research strives to address the gap in the literature surrounding companies which identify with the philosophical values associated with the Free Software movement, which have historically been associated with Open Source businesses. It investigates whether ethically-motivated Free Software identified companies resemble social entrepreneurships. This work also examines whether there are significant differences between the business practices of Free Software identified companies, Free Software, and Open Source enterprises in order to assess if it is appropriate to address them as a group. The study is based on seven case studies, and includes one company which is a Free Software business, but does not identify with the Free Software philosophy, as well as one company which is ethically-motivated but identifies with Open Source rather than Free Software. The results indicate that there is good reason to believe that adherence to Free Software philosophy creates socially-aware businesses, which may be social entrepreneurships. No problems were discovered with the practice of grouping together Free Software and Open Source companies in the study of business practices, provided that a broad definition of success is used.
Keywords: free software; open source software; public good; small business; social entrepreneurship; social ventures

A Study of the Relationships between Source Code Metrics and Attractiveness in Free Software Projects - Meirelles, Paulo; Santos Jr., Carlos; Miranda, Joao; Kon, Fabio; Terceiro, Antonio; Chavez, Christina (Proceedings of the 2010 Brazilian Symposium on Software Engineering, 2010)
A significant number of Free Software projects has been widely used and considered successful. However, there is an even larger number of them that cannot overcome the initial steps towards building an active community of users and developers. In this study, we investigated whether there are relationships between source code metrics and attractiveness, i.e., the ability of a project to attract users and developers. To verify these relationships, we analyzed 6,773 Free Software projects from the SourceForge.net repository. The results indicated that attractiveness is indeed correlated to some source code metrics. This suggests that measurable attributes of the project source code somehow affect the decision to contribute to and adopt a Free Software. The findings described in this paper show that it is relevant for project leaders to monitor source code quality, particularly a few objective metrics, since these can have a positive influence in projects chances of forming a community of contributors and users around their software, enabling further enhancement in quality.
Keywords: source code; source code analysis; sourceforge; user satisfaction; users

Success and Abandonment in Open Source Commons: Selected Findings from an Empirical Study of Sourceforge.net Projects - Schweik, C. M.; English, R.; Paienjton, Q.; Haire, S. (Second International Workshop on Building Sustainable Open Source Communities (OSCOMM 2010), 2010)
Some open source software collaborations are sustained over long periods of time and across several versions of a software product, while others become abandoned even before the first version of the product has been developed. In this study, we identify factors that might be responsible for one or the other of these collaborative trajectories. We examine 107,747 open source software projects hosted on Sourceforge.net in August 2006 using data available through the FLOSSmole Project. We employ Classification and Regression Tree modeling and Random Forests statistical approaches to begin to establish an understanding of how various project attributes, especially physical and community ones, contribute to project success or abandonment. We find that factors associated with success and abandonment differ for projects in the early stage of development (pre-first release) compared to projects that have had a first release, and that product utility, project vision, leadership, and group-size are associated with success in open source collaborations. We also find that successful open source projects exist across all types of software and not simply in areas associated with the open source “movement.” Other evidence suggests that Sourceforge.net may play an important role in “intellectual match-making.”
Keywords: abandonment; flossmole; metadata; project failure; project success; sourceforge; time

Summarizing software artifacts: a case study of bug reports - Rastkar, Sarah; Murphy, Gail C.; Murray, Gabriel (Proceedings of the 32nd ACM/IEEE International Conference on Software Engineering - Volume 1, 2010)
Many software artifacts are created, maintained and evolved as part of a software development project. As software developers work on a project, they interact with existing project artifacts, performing such activities as reading previously filed bug reports in search of duplicate reports. These activities often require a developer to peruse a substantial amount of text. In this paper, we investigate whether it is possible to summarize software artifacts automatically and effectively so that developers could consult smaller summaries instead of entire artifacts. To provide focus to our investigation, we consider the generation of summaries for bug reports. We found that existing conversation-based generators can produce better results than random generators and that a generator trained specifically on bug reports can perform statistically better than existing conversation-based generators. We demonstrate that humans also find these generated summaries reasonable indicating that summaries might be used effectively for many tasks.
Keywords: bug reports; eclipse; gnome; human-centric software engineering; kde; machine learning; mozilla

Survival analysis on the duration of open source projects - Samoladas, Ioannis; Lefteris Angelis; Ioannis Stamelos (Information and Software Technology, 2010)
Context Open source (FLOSS) project survivability is an important piece of information for many open source stakeholders. Coordinators of open source projects would like to know the chances for the survival of the projects they coordinate. Companies are also interested in knowing how viable a project is in order to either participate or invest in it, and volunteers want to contribute to vivid projects. Objective The purpose of this article is the application of survival analysis techniques for estimating the future development of a FLOSS project. Method In order to apply such approach, duration data regarding FLOSS projects from the FLOSSMETRICS (This work was partially supported by the European Community’s Sixth Framework Program under the Contract FP6-033982) database were collected. Such database contains metadata for thousands of FLOSS projects, derived from various forges. Subsequently, survival analysis methods were employed to predict the survivability of the projects, i.e. their probability of continuation in the future, by examining their duration, combined with other project characteristics such as their application domain and number of committers. Results It was shown how probability of termination or continuation may be calculated and how a prediction model may be built to upraise project future. In addition, the benefit of adding more committers to FLOSS projects was quantified. Conclusion Analysis results demonstrate the usefulness of the proposed framework for assessing the survival probability of a FLOSS project.
Keywords: flossmetrics; prediction; source code; survival analysis

Sustainability of Open-Source Projects: A Longitudinal Study - Chengular-Smith, I.; Sidorova, Anna; Daniel, Sherae L. (Journal of the Association for Information Systems, 2010)
This paper examines the factors that influence the long-term sustainability of FLOSS projects. A model of project sustainability based on organizational ecology is developed and tested empirically. Data about activity and contribution patterns over the course of five years for 2,772 projects registered with SourceForge is analyzed. Our results suggest that the size of the project’s development base, project age and the size of niche occupied by the project are positively related to the project’s ability to attract user and/or developer resources. The ability to attract resources is an indicator of the perceived project legitimacy, which in turn is a strong predictor of the project’s future sustainability. Thus a project’s ability to attract developer and user resources is shown to play a mediating role between the demographic (size and age) and ecological (niche) characteristics of the project and its future sustainability. Our results support the applicability of tenets of organizational ecology related to the liability of smallness, the liability of newness, and population characteristics (niche size) to the FLOSS development environment. The implications of the results for future research and practice are discussed.
Keywords: contribution; developers; sourceforge; sustainability

Towards a bayesian approach in modeling the disclosure of unique security faults in open source projects - Anbalagan, Prasanth; Vouk, Mladen (Software Reliability Engineering (ISSRE), 2010 IEEE 21st International Symposium on, 2010)
Software security has both an objective and a subjective component. A lot of the information available about that today is focused on security vulnerabilities and their disclosure. It is less frequent that security breaches and failures rates are reported, even in open source projects. Disclosure of security problems can take several forms. A disclosure can be accompanied by a release of the fix for the problem, or not. The latter category can be further divided into ”voluntary” and ”involuntary” security issues. In widely used software there is also considerable variability in the operational profile under which the software is used. This profile is further modified by attacks on the software that may be triggered by security disclosures. Therefore a comprehensive model of software security qualities of a product needs to incorporate both objective measures, such as security problem disclosure, repair and, failure rates, as well as less objective metrics such as implied variability in the operational profile, influence of attacks, and subjective impressions of exposure and severity of the problems, etc. We show how a classical Bayesian model can be adapted for use in the security context. The model is discussed and assessed using data from three open source software project releases. Our results show that the model is suitable for use with a certain subset of disclosed security faults, but that additional work will be needed to identify appropriate shape and scaling functions that would accurately reflect end-user perceptions associated with security problems.
Keywords: security

Towards an Openness Rating System for Open Source Software - Bein, Wolfgang; Jeffery, Clinton (2010 43rd Hawaii International Conference on System Sciences (HICSS 2010), 2010)
Many open source software projects are not very open to third party developers. The point of open source is to enable anyone to fix bugs or add desired capabilities without holding them hostage to the original developers. This principle is important because an open source project's developers may be unresponsive or unable to meet third party needs, even if funding support for requested improvements is offered.This paper presents a simple rating system for evaluating the openness of software distributions. The rating system considers factors such as platform portability, documentation, licensing, and contribution policy. Several popular open source products are rated in order to illustrate the efficacy of the rating system.
Keywords: alice; case study; contribution; documentation; freespire; galib; latex; license; linux; linux kernel; mediaportal; openness; openoffice; opensolaris; rating; unicon

Trends That Affect Temporal Analysis Using SourceForge Data - MacLean, Alexander C.; Pratt, Landon J.; Krein, Jonathan L.; Knutson, Charles D. (5th Workshop on Public Data about Software Development (WoPDaSD 2010), 2010)
SourceForge is a valuable source of software artifact data for researchers who study project evolution and developer behavior. However, the data exhibit patterns that may bias temporal analyses. Most notable are cliff walls in project source code repository timelines, which indicate large commits that are out of character for the given project. These cliff walls often hide significant periods of development and developer collaboration—a threat to studies that rely on SourceForge repository data. We demonstrate how to identify these cliff walls, discuss reasons for their appearance, and propose preliminary measures for mitigating their effects in evolution-oriented studies.
Keywords: cliff walls; committers; cvs; evolution; growth; source code; sourceforge; time; time series

The Ultimate Debian Database: Consolidating bazaar metadata for Quality Assurance and data mining - Nussbaum, Lucas; Zacchiroli, Stefano (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
FLOSS distributions like RedHat and Ubuntu require a lot more complex infrastructures than most other FLOSS projects. In the case of community-driven distributions like Debian, the development of such an infrastructure is often not very organized, leading to new data sources being added in an impromptu manner while hackers set up new services that gain acceptance in the community. Mixing and matching data is then harder than should be, albeit being badly needed for Quality Assurance and data mining. Massive refactoring and integration is not a viable solution either, due to the constraints imposed by the bazaar development model. This paper presents the Ultimate Debian Database (UDD), which is the countermeasure adopted by the Debian project to the above "data hell". UDD gathers data from various data sources into a single, central SQL database, turning Quality Assurance needs that could not be easily implemented before into simple SQL queries. The paper also discusses the customs that have contributed to the data hell, the lessons learnt while designing UDD, and its applications and potentialities for data mining on FLOSS distributions.
Keywords: debian; metadata; udd

Using Open Source Software Components to Implement a Modular Web 2.0 Design for Map-Based Discussions - Leahy, Michael G.; Hall, G. Brent (International Journal of Open Source Software and Processes, 2010)
This paper discusses the research-based origins and modular architecture of an open source geospatial tool that facilitates synchronous individual and group discussions using the medium of a Web map service. The software draws on existing open source geospatial projects and associated libraries and techniques that have evolved as part of the new generation of Web applications. The purpose of the software is discussed, highlighting the fusion of existing open source projects to produce new tools. Two case studies are briefly discussed to illustrate the value an open source approach brings to communities who would remain otherwise outside the reach of proprietary software tools. The paper concludes with comments on the project’s future evolution as an open source participatory mapping platform.

Using the DEMO methodology for modeling open source software development processes - Huysmans, Philip; Ven, Kris; Verelst, Jan (Information and Software Technology, 2010)
Context Open source software development (OSSD) process modeling has received increasing interest in recent years. These efforts aim to identify common elements in the development process between multiple open source software (OSS) projects. However, the complexity inherent to OSSD process modeling puts significant demands on the modeling language. Objective In this paper, we propose that the Design and Engineering Methodology for Organizations (DEMO) may provide an interesting alternative to develop OSSD process models. DEMO exhibits two unique features within the context of OSSD process modeling. First, DEMO analyzes processes at the ontological level and provides high-level process descriptions, instead of focusing on the implementation level. Second, DEMO studies the communication patterns between human actors, instead of the sequences in which activities are performed. Method We investigate the feasibility of using DEMO to construct OSSD process models by means of a case study. DEMO models were constructed to describe the NetBeans Requirements and Release process. In addition, the quality of these DEMO models was evaluated using a quality framework for conceptual modeling. Results Our results showed that our DEMO models exhibited a high level of abstraction, thereby reducing the complexity of the OSSD process models. In addition, the evaluation of the models developed in this paper by using the quality framework for conceptual modeling showed that the models were of high quality. Conclusions We have shown that the DEMO methodology can be successfully used to model OSSD processes and to obtain abstract and high-quality OSSD process models. However, given some potential drawbacks with respect to understandability and implementability, we primarily propose the use of DEMO within OSSD process modeling as an analysis tool that should be complemented with other techniques and models for communication and reenactment purposes.
Keywords: DEMO; Enterprise ontology; open source software; Software process modeling

Validity concerns in software engineering research - Wright, Hyrum K.; Kim, Miryung (Proceedings of the FSE/SDP workshop on Future of software engineering research - FoSER '10, 2010)
Empirical studies that use software repository artifacts have become popular in the last decade due to the ready availability of open source project archives. In this paper, we survey empirical studies in the last three years of ICSE and FSE proceedings, and categorize these studies in terms of open source projects vs. proprietary source projects and the diversity of subject programs used in these studies. Our survey has shown that almost half (49%) of recent empirical studies used solely open source projects. Existing studies either draw general conclusions from these results or explicitly disclaim any conclusions that can extend beyond specific subject software. We conclude that researchers in empirical software engineering must consider the external validity concerns that arise from using only several well-known open source software projects, and that discussion of data source selection is an important discussion topic in software engineering research. Furthermore, we propose a community research infrastructure for software repository benchmarks and sharing the empirical analysis results, in order to address external validity concerns and to raise the bar for empirical software engineering research that analyzes software artifacts.
Keywords: flossmole cited

Validity of network analyses in Open Source Projects - Nia, Roozbeh; Christian Bird; Devanbu, Premkumar; Filkov, Vladimir (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
Social network methods are frequently used to analyze networks derived from Open Source Project communication and collaboration data. Such studies typically discover patterns in the information flow between contributors or contributions in these projects. Social network metrics have also been used to predict defect occurrence. However, such studies often ignore or side-step the issue of whether (and in what way) the metrics and networks of study are influenced by inadequate or missing data. In previous studies email archives of OSS projects have provided a useful trace of the communication and co-ordination activities of the participants. These traces have been used to construct social networks that are then subject to various types of analysis. However, during the construction of these networks, some assumptions are made, that may not always hold; this leads to incomplete, and sometimes incorrect networks. The question then becomes, do these errors affect the validity of the ensuing analysis? In this paper we specifically examine the stability of network metrics in the presence of inadequate and missing data. The issues that we study are: 1) the effect of paths with broken information flow (i.e. consecutive edges which are out of temporal order) on measures of centrality of nodes in the network, and 2) the effect of missing links on such measures. We demonstrate on three different OSS projects that while these issues do change network topology, the metrics used in the analysis are stable with respect to such changes.
Keywords: apache; email archives; mailing lists; missing data; mysql; perl; social networks

Warehousing and Studying Open Source Versioning Metadata - van Antwerp, M.; Madey, G. (IFIP Advances in Information and Communication Technology Open Source Software: New Horizons (OSS 2010), 2010)
In this paper, we describe the downloading and warehousing of Open Source Software (OSS) versioning metadata from SourceForge, BerliOS Developer, and GNU Savannah. This data enables and supports research in areas such as software engineering, open source phenomena, social network analysis, data mining, and project management. This newly-formed database containing Concurrent Versions System (CVS) and Subversion (SVN) metadata offers new research opportunities for large-scale OSS development analysis. The CVS and SVN data is juxtaposed with the SourceForge.net Research Data Archive [5] for the purpose of performing more powerful and interesting queries. We also present an initial statistical analysis of some of the most active projects.
Keywords: berlios; cvs; savannah; scm; sourceforge; srda; subversion; svn

Weaving a Semantic Web Across OSS Repositories - Olivier Berger; Valentin Vlasceanu; Christian Bac; Quang Vu Dang; Lauriere, Stéphane (International Journal of Open Source Software and Processes, 2010)
Several public repositories and archives of “facts” about libre software projects, maintained either by open source communities or by research communities, have been flourishing over the Web in recent years. These have enabled new analysis and support for new quality assurance tasks. This paper presents some complementary existing tools, projects and models proposed both by OSS actors or research initiatives that are likely to lead to useful future developments in terms of study of the FLOSS phenomenon, and also to the very practitioners in the FLOSS development projects. A goal of the research conducted within the HELIOS project is to address bugs traceability issues. In this regard, the authors investigate the potential of using Semantic Web technologies in navigating between many different bugtracker systems scattered all over the open source ecosystem. By using Semantic Web techniques, it is possible to interconnect the databases containing data about open-source software projects development, which enables OSS partakers to identify resources, annotate them, and further interlink those using dedicated properties and collectively designing a distributed semantic graph.
Keywords: archive; bug; bugtracker; database; debian; forge; interoperability; ontology; OSLC-CM; RDF; repository of repositories; semantic; semantic Web

What Makes a Good Bug Report? - Zimmermann, Thomas; Premraj, Rahul; Bettenburg, Nicolas; Sascha Just; Schroter, Adrian; Weiss, Cathrin (IEEE Transactions on Software Engineering, 2010)
In software development, bug reports provide crucial information to developers. However, these reports widely differ in their quality. We conducted a survey among developers and users of APACHE, ECLIPSE, and MOZILLA to find out what makes a good bug report. The analysis of the 466 responses revealed an information mis- match between what developers need and what users supply. Most developers consider steps to reproduce, stack traces, and test cases as helpful, which are at the same time most difficult to provide for users. Such insight is helpful to design new bug tracking tools that guide users at collecting and providing more helpful information. Our CUEZILLA prototype is such a tool and measures the quality of new bug reports; it also recommends which elements should be added to improve the quality. We trained CUEZILLA on a sample of 289 bug reports, rated by developers as part of the survey. In our experiments, CUEZILLA was able to predict the quality of 31–48% of bug reports accurately.
Keywords: bug report; Survey

What's all the FOSS? - Huett, Jason B.; Sharp, Jason H.; Huett, Kimberly C. (International Journal of Open Source Software and Processes, 2010)
Philosophical, financial, practical, and pedagogical considerations have prompted educators to take a serious look at Free and Open Source Software (FOSS) as an alternative to proprietary software. To better understand the overall concept of FOSS, this article provides a brief history of FOSS as well as a summary of its definition, philosophy, and major areas of research, including strengths and limitations, diffusion in education and educational uses as well as a look at the opportunities, issues, and challenges associated with FOSS. In conclusion, the authors speculate how FOSS, along with advances in E-Learning and other emerging technologies, will positively shape our educational future.

When process data quality affects the number of bugs: Correlations in software engineering datasets - Bachmann, Adrian; Bernstein, Abraham (2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010), 2010)
Software engineering process information extracted from version control systems and bug tracking databases are widely used in empirical software engineering. In prior work, we showed that these data are plagued by quality deficiencies, which vary in its characteristics across projects. In addition, we showed that those deficiencies in the form of bias do impact the results of studies in empirical software engineering. While these findings affect software engineering researchers the impact on practitioners has not yet been substantiated. In this paper we, therefore, explore (i) if the process data quality and characteristics have an influence on the bug fixing process and (ii) if the process quality as measured by the process data has an influence on the product (i.e., software) quality. Specifically, we analyze six Open Source as well as two Closed Source projects and show that process data quality and characteristics have an impact on the bug fixing process: the high rate of empty commit messages in Eclipse, for example, correlates with the bug report quality. We also show that the product quality - measured by number of bugs reported - is affected by process data quality measures. These findings have the potential to prompt practitioners to increase the quality of their software process and its associated data quality.
Keywords: apache; bug reports; eclipse; gnome; log files; mozilla; netbeans; openoffice.org; version control

1st International Workshop on: ‘Designing for Participatory Learning’ Building from Open Source Success to Develop Free Ways to Share and Learn - Andreas Meiszner; Ioannis Stamelos; Sowe, Sulayman (OSS2009: Open Source Ecosystems: Diverse Communities Interacting (IFIP 2.13), 2009)
The Open Source world shows how volunteer collaboration can lead to great products and to great learning. We want to further explore at this workshop what happens using approaches from that community to break barriers between teachers and learners for today’s Internet-savvy young people to design and co-construct sites for participatory learning. The aim of this workshop is to explore the barriers for this type of learning in higher education settings. Content creation, knowledge exchange, community dynamics, and the impact on the boundary between formal and informal education are key subjects of this workshop.

4th International Workshop on Public Data about Software Development - González-Barahona, Jesús; Squire, Megan; Izquierdo-Cortázar, Daniel (OSS2009: Open Source Ecosystems: Diverse Communities Interacting (IFIP 2.13), 2009)
Libre (free, open source) projects offer publicly available data sources. The research community is starting to produce, use and exchange large data sets of information. These data sets have to be retrieved, purged, described, and can be published for public consumption by other groups. Their availability allows for the decoupling of research activities, the reproducibility of research results, and even the collaboration (and competition) in the analysis of data. This activity is frequently presented at workshops and conferences, but since the focus of these conferences is not specific to the use of public data, discussions of techniques and experiences are not as deep and fruitful as they could be. This workshop is once again (for the fourth year in a row) such a place. We will host discussions specifically about these sorts of public data sets about software development, how they are retrieved, how they can be analyzed and mined, how they can be exchanged and extended.

An Agent Simulation Study on Conflict, Community Climate and Innovation in Open Source Communities - Yilmaz, Levent (International Journal of Open Source Software and Processes, 2009)
More than ever the complexity of innovation requires group efforts, as teams of scientists and engineers from diverse backgrounds work together to solve problems. One of the significant problems in understanding emergence of innovation involves how virtual innovation organizations and communities govern and coordinate to maximize innovation output. An agent simulation study is conducted to examine the impact of culture and conflict management styles on collective creativity in open source innovation systems. Findings suggest that decentralized coordination schemes such as emergent selection such as found in utility communities and moderate degrees of assertiveness and cooperation for conflict management result in higher incidence of innovation.

Amassing and indexing a large sample of version control systems: towards the census of public source code history - Audris Mockus (6th IEEE Working Conference on Mining Software Repositories, 2009)
The source code and its history represent the output and process of software development activities and are an in- valuable resource for study and improvement of software development practice. While individual projects and groups of projects have been extensively analyzed, some fundamental questions, such as the spread of innovation or genealogy of the source code, can be answered only by considering the entire universe of publicly available source code and its history. We describe methods we developed over the last six years to gather, index, and update an approximation of such a universal repository for publicly accessible version control systems and for the source code inside a large corporation. While challenging, the task is achievable with limited resources. The bottlenecks in network bandwidth, processing, and disk access can be dealt with using inherent parallelism of the tasks and suitable tradeoffs between the amount of storage and computations, but a completely automated discovery of public version control systems may require enticing participation of the sampled projects. Such universal repository would allow studies of global properties and origins of the source code that are not possible through other means.
Keywords: bazaar; cvs; flossmole; git; mercurial; source code; sourceforge; subversion; version control

On the Analysis of Contributions from Privileged Users in Virtual Open Communities - Ortega, Felipe; Izquierdo-Cortázar, Daniel; González-Barahona, Jesús M.; Gregorio Robles (2009 42nd Hawaii International Conference on System Sciences, 2009)
Collaborative projects built around virtual communities on the Internet have gained momentum over the last decade. Nevertheless, their rapid growth rate rises some questions:which is the most effective approach to manage and organize their content creation process? Can these communities scale, controlling their projects as their size continues to grow over time? To answer these questions, we undertake a quantitative analysis of privileged users in FLOSS development projects and in Wikipedia. From our results, we conclude that the inequality level of user contributions in both types of initiatives is remarkably distinct, even though both communities present almost identical patterns regard-ing the number of distinct contributors per ﬁle (in FLOSS projects) or per article (in Wikipedia). As a result, totally open projects like Wikipedia can effectively deal with faster growing rates, while FLOSS projects may be affected by bottlenecks on committers who play critical roles.

Analysis of Open Source Software Development Iterations by Means of Burst Detection Techniques - Rossi, Bruno; Russo, Barbara; Succi, Giancarlo (OSS2009: Open Source Ecosystems: Diverse Communities Interacting (IFIP 2.13), 2009)
A highly efficient bug fixing process and quick release cycles are considered key properties of the open source software development methodology. In this paper, we study the relation between code activities (such as lines of code added per commit), bug fixing activities, and software release dates in a subset of open source projects. To study the phenomenon, we gathered a large data set about the evolution of 5 major open source projects. We compared activities by means of a burst detection technique to discover temporal peaks in time-series. We found quick adaptation of issue tracking activities in proximity of releases, and a distribution of coding activities across releases. Results show the importance of the application type/domain for the evaluation of the development process.

Analyzing Software Licenses in Open Architecture Software Systems - Alspaugh, Thomas; Hazeline U. Asuncion; Walt Scacchi (Proceedings of the Workshop on Emerging Trends in FLOSS Research and Development, 2009)

Assessing FLOSS Communities: An Experience Report from the QualOSS Project - Izquierdo-Cortazar, Daniel; Gregorio Robles; González-Barahona, Jesús; Deprez, Jean-Christophe (OSS2009: Open Source Ecosystems: Diverse Communities Interacting (IFIP 2.13), 2009)
This paper presents work done in the QualOSS (Quality of Open Source Software) research project,which aims at building a methodology and tools to help in the assessment of the quality of FLOSS (free, libre, open source software) endeavors. In particular, we introduce the research done to evaluate the FLOSS endeavor communities. Following the Goal-Question-Metric paradigm, QUALOSS describes goals, the associated questions and then metrics that allow to answer the questions.

Assigning bug reports using a vocabulary-based expertise model of developers - Matter, Dominique; Kuhn, Adrian; Nierstrasz, Oscar (2009 6th IEEE International Working Conference on Mining Software Repositories (MSR)2009 6th IEEE International Working Conference on Mining Software Repositories, 2009)
For popular software systems, the number of daily submitted bug reports is high. Triaging these incoming reports is a time consuming task. Part of the bug triage is the assignment of a report to a developer with the appropriate expertise. In this paper, we present an approach to automatically suggest developers who have the appropriate expertise for handling a bug report. We model developer expertise using the vocabulary found in their source code contributions and compare this vocabulary to the vocabulary of bug reports. We evaluate our approach by comparing the suggested experts to the persons who eventually worked on the bug. Using eight years of Eclipse development as a case study, we achieve 33.6% top-1 precision and 71.0% top-10 recall.
Keywords: bug reports; bugzilla; develect; developers; eclipse; expertise; scm