Estimating Development Effort in Free/Open Source Software Projects by Mining Software Repositories: A Case Study of OpenStack - Gregorio Robles; González-Barahona, Jesús M.; Cervigón, Carlos; Capiluppi, Andrea; Izquierdo-Cortázar, Daniel (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
Because of the distributed and collaborative nature of free / open source software (FOSS) projects, the development effort invested in a project is usually unknown, even after the software has been released. However, this information is becoming of major interest, especially ---but not only--- because of the growth in the number of companies for which FOSS has become relevant for their business strategy. In this paper we present a novel approach to estimate effort by considering data from source code management repositories. We apply our model to the OpenStack project, a FOSS project with more than 1,000 authors, in which several tens of companies cooperate. Based on data from its repositories and together with the input from a survey answered by more than 100 developers, we show that the model offers a simple, but sound way of obtaining software development estimations with bounded margins of error.
Keywords: effort estimation; free software; mining software repositories; open source; openstack

Evaluating Software Product Quality: A Systematic Mapping Study - Ouhbi, Sofia; Idri, Ali; Aleman, Jose Luis Fernandez; Toval, Ambrosio (2014 Joint Conference of the International Workshop on Software Measurement IWSM-MENSURA, 2014)
Evaluating software product quality (SPQ) is an important task to ensure the quality of software products. In this paper a systematic mapping study was performed to summarize the existing SPQ evaluation (SPQE) approaches in literature and to classify the selected studies according to seven classification criteria: SPQE approaches, research types, empirical types, data sets used in the empirical evaluation of these studies, artifacts, SQ models, and SQ characteristics. Publication channels and trends were also identified. 57 papers were selected. The results show that the main publication sources of the papers identified were journals. Data mining techniques are the most frequently approaches reported in literature. Solution proposals were the main research type identified. The majority of the selected papers were history-based evaluations using existing data, which were mainly obtained from open source software projects and domain specific projects. Source code was the main artifacts used by SPQE approaches. Well-known SQ models were mentioned by half of the selected papers and reliability is the SQ characteristic through which SPQE was mainly achieved. SPQE-related subjects seem to attract more interest from researchers since the past years.

An Exploration of Code Quality in FOSS Projects - Ahmed, Iftekhar; Ghorashi, Soroush; Jensen, Carlos (Open Source Software: Mobile Open Source Technologies, 2014)
It is a widely held belief that Free/Open Source Software (FOSS) development leads to the creation of software with the same, if not higher quality compared to that created using proprietary software development models. However there is little research on evaluating the quality of FOSS code, and the impact of project characteristics such as age, number of core developers, code-base size, etc. In this exploratory study, we examined 110 FOSS projects, measuring the quality of the code and architectural design using code smells. We found that, contrary to our expectations, the overall quality of the code is not affected by the size of the code base, but that it was negatively impacted by the growth of the number of code contributors. Our results also show that projects with more core developers don’t necessarily have better code quality.
Keywords: Code Quality; FOSS; open source software; success metrics

Exploring the Ecosystem of Software Developers on GitHub and Other Platforms - Wu, Yu; Kropczynski, Jessica; Shih, Patrick C.; Carroll, John M. (Proceedings of the Companion Publication of the 17th ACM Conference on Computer Supported Cooperative Work & Social Computing, 2014)
GitHub provides various social features for developers to collaborate with others. Those features are important for developers to coordinate their work (Dabbish et al., 2012; Marlow et al., 2013). We hypothesized that the social system of GitHub users was bound by system interactions such that contributing to similar code repositories would lead to users following one another on GitHub or vice versa. Using a quadratic assignment procedure (QAP) correlation, however, only a weak correlation among followship and production activities (code, issue, and wiki contributions) was found. Survey with GitHub users revealed an ecosystem on the Internet for software developers, which includes many platforms, such as Forrst, Twitter, and Hacker News, among others. Developers make social introductions and other interactions on these platforms and engage with one anther on GitHub. Due to these preliminary findings, we describe GitHub as a part of a larger ecosystem of developer interactions.
Keywords: ecosystem; follow; github; social connection

Filling the Gaps of Development Logs and Bug Issue Data - Romo, Bilyaminu Auwal; Capiluppi, Andrea; Hall, Tracy (Proceedings of The International Symposium on Open Collaboration, 2014)
It has been suggested that the data from bug repositories is not always in sync or complete compared to the logs detailing the actions of developers on source code. In this paper, we trace two sources of information relative to software bugs: the change logs of the actions of developers and the issues reported as bugs. The aim is to identify and quantify the discrepancies between the two sources in recording and storing the developer logs relative to bugs. Focussing on the databases produced by two mining software repository tools, CVSAnalY and Bicho, we use part of the SZZ algorithm to identify bugs and to compare how the "defects-fixing changes" are recorded in the two databases. We use a working example to show how to do so. The results indicate that there is a significant amount of information, not in sync when tracing bugs in the two databases. We, therefore, propose an automatic approach to re-align the two databases, so that the collected information is mirrored and in sync.
Keywords: Bug traceability; bug-fixing commits

FLOSS 2013: A Survey Dataset About Free Software Contributors: Challenges for Curating, Sharing, and Combining - Gregorio Robles; Reina, Laura Arjona; Serebrenik, Alexander; Vasilescu, Bogdan; González-Barahona, Jesús M. (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
In this data paper we describe a data set obtained by means of performing an on-line survey to over 2,000 Free Libre Open Source Software (FLOSS) contributors. The survey includes questions related to personal characteristics (gender, age, civil status, nationality, etc.), education and level of English, professional status, dedication to FLOSS projects, reasons and motivations, involvement and goals. We describe as well the possibilities and challenges of using private information from the survey when linked with other, publicly available data sources. In this regard, an example of data sharing will be presented and legal, ethical and technical issues will be discussed.
Keywords: anonymization; data combining; data sharing; ethics; free software; microdata; msr data showcase; open data; open source; privacy; Survey

Flow Research SXP Agile Methodology for FOSS Projects - Peñalver Romero, GladysMarsi; Leyva Samada, LisandraIsabel; Abad, AbelMeneses (Open Source Software: Mobile Open Source Technologies, 2014)
This paper aims to explain a procedure that takes into account the different research processes carried out in developing an open-source, allowing control and management. This study is the SXP methodology applied in this type of project was carried out, allowing the validity of the basis of this research.
Keywords: methodology SXP; open-source; production; research; Software

Forge++: The changing landscape of FLOSS development - Squire, Megan (47th International Hawai'i Conference on System Sciences (HICSS-47), 2014)
Software forges are centralized online systems that provide useful tools to help distributed development teams work together, especially in free, libre, and open source software (FLOSS). Forge-provided tools may include web space, version control systems, mailing lists and communication forums, bug tracking systems, file downloads, wikis, and the like. Empirical software engineering researchers can mine the artifacts from these tools to better understand how FLOSS is made. As the landscape of distributed software development has grown and changed, the tools needed to make FLOSS have changed as well. There are three newer tools at the center of FLOSS development today: distributed version control based forges (like Github), programmer question-and-answer communities (like Stack Overflow), and pastebin tools (like Gist or Pastebin.com). These tools are extending and changing the toolset used for FLOSS development, and redefining what a software forge looks like. The main contributions of this paper are to describe each of these tools, to identify the data and artifacts available for mining from these tools, and to outline some of the ways researchers can use these artifacts to continue to understand how FLOSS is made.

FOSS Service Management and Incidences - Ortiz, SusanaSánchez; Pérez Benitez, Alfredo (Open Source Software: Mobile Open Source Technologies, 2014)
The Free Open Source Software (FOSS) solutions have been reaching a high demand, usage and global recognition, not only in the development of applications for companies and institutions also in the management of services and incidents. With the upswing of Information Technology (IT), the development of tools that enable the reporting of problems and incidents on any organization or company is necessary. Every day you need more applications, software generally, that make easier the user’s actions. This paper describes the need to use these tools and recount the development of a web application that allows the management of reports and incidents from users of Nova, the GNU/Linux Cuban distribution.
Keywords: FOSS; service management and incidences

Free/Open Source Software projects as early MOOCs - Robles, G.; Plaza, H.; Gonzalez-Barahona, J.M. (Global Engineering Education Conference (EDUCON), 2014 IEEE, 2014)
This paper presents Free/Libre/Open Source Software (FLOSS) Projects as early Massive Online Open Courses (MOOCs). Being software development a process where learning and collaboration is of major importance, FLOSS projects have in common many characteristics with MOOCs. This is because many FLOSS projects (such as Linux, Apache, GNOME or KDE, among others) are massive, they are open to anyone to participate, and are driven mainly by telematic means. We therefore present the research literature that has studied FLOSS projects from points of view that are close to learning and discuss how the FLOSS community has approached many of the issues related to acquiring knowledge and skills over the Internet and compare them to how currently MOOCs, both xMOOCs and cMOOCs, address these situations.
Keywords: education; FLOSS; learning; mooc

Gentoo Package Dependencies over Time - Bloemen, Remco; Amrit, Chintan; Kuhlmann, Stefan; Ordóñez–Matamoros, Gonzalo (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
Open source distributions such as Gentoo need to accurately track dependency relations between software packages in order to install working systems. To do this, Gentoo has a carefully authored database containing those relations. In this paper, we extract the Gentoo package dependency graph and its changes over time. The final dependency graph spans 15 thousand open source projects and 80 thousand dependency relations. Furthermore, the development of this graph is tracked over time from the beginning of the Gentoo project in 2000 to the first quarter of 2012, with monthly resolution. The resulting dataset provides many opportunities for research. In this paper we explore cluster analysis to reveals meaningful relations between packages and in a separate paper we analyze changes in the dependencies over time to get insights in the innovation dynamics of open source software.
Keywords: dependencies; gentoo; graph; INNOVATION

Governance of Open Source Electronic Health Record Projects: A Successful Case of a Hybrid Model - Placide Poba-Nzaou; Josianne Marsan; Guy Pare; Louis Raymond (47th International Hawai'i Conference on System Sciences (HICSS-47), 2014)
Electronic Health Records (EHRs) are at the heart of most health system reforms. As an increasing number of hospitals are adopting open source EHRs and as many questions are still unanswered for potential adopters of open source EHRs, analyzing the governance of such systems has become important. Due to the increased diversity of sponsors and stakeholders of open source software (OSS) over the past few years, numerous governance models of OSS projects have emerged. In contrast to earlier “community-managed” governance model s, these emergent models are characterized by the sponsorship of a corporation or a not-for-profit entity or by other hybrid forms. This paper reports on the investigation of such a hybrid model of open source EHR project governance adopted with success by a large Canadian hospital. The case study provides rich insights for other hospitals wishing to adopt an EHR of the open source type.

Hackers on Forking - Nyman, Linus (The International SymposiumProceedings of The International Symposium on Open Collaboration - OpenSym '14, 2014)
All open source licenses allow the copying of an existing body of code for use as the basis of a separate development project. This practice is commonly known as forking the code. This paper presents the results of a study in which 11 programmers were interviewed about their opinions on the right to fork and the impact of forking on open source software development. The results show that there is a general consensus among programmers' views regarding both the favourable and unfavourable aspects that stem from the right to fork. Interestingly, while all programmers noted potential downsides to the right to fork, it was seen by all as an integral component of open source software, and a right that must not be infringed regardless of circumstance or outcome.

How Do Social Interaction Networks Influence Peer Impressions Formation? A Case Study - Bosu, Amiangshu; Carver, JeffreyC. (Open Source Software: Mobile Open Source Technologies, 2014)
Due to their lack of physical interaction, Free and Open Source Software (FOSS) participants form impressions of their teammates largely based on sociotechnical mechanisms including: code commits, code reviews, mailing-lists, and bug comments. These mechanisms may have different effects on peer impression formation. This paper describes a social network analysis of the WikiMedia project to determine which type of interaction has the most favorable characteristics for impressions formation. The results suggest that due to lower centralization, high interactivity, and high degree of interactions between participants, the code review interactions have the most favorable characteristics to support impression formation among FOSS participants.
Keywords: COLLABORATION; FOSS; open source; OSS; social network analysis

How Social Q&A Sites Are Changing Knowledge Sharing in Open Source Software Communities - Vasilescu, Bogdan; Serebrenik, Alexander; Devanbu, Prem; Filkov, Vladimir (Proceedings of the 17th ACM Conference on Computer Supported Cooperative Work & Social Computing, 2014)
Historically, mailing lists have been the preferred means for coordinating development and user support activities. With the emergence and popularity growth of social Q&A sites such as the StackExchange network (e.g., StackOverflow), this is beginning to change. Such sites offer different socio-technical incentives to their participants than mailing lists do, e.g., rich web environments to store and manage content collaboratively, or a place to showcase their knowledge and expertise more vividly to peers or potential recruiters. A key difference between StackExchange and mailing lists is gamification, i.e., StackExchange participants compete to obtain reputation points and badges. In this paper, we use a case study of R (a widely-used tool for data analysis) to investigate how mailing list participation has evolved since the launch of StackExchange. Our main contribution is the assembly of a joint data set from the two sources, in which participants in both the textttr-help mailing list and StackExchange are identifiable. This permits their activities to be linked across the two resources and also over time. With this data set we found that user support activities show a strong shift away from textttr-help. In particular, mailing list experts are migrating to StackExchange, where their behaviour is different. First, participants active both on textttr-help and on StackExchange are more active than those who focus exclusively on only one of the two. Second, they provide faster answers on StackExchange than on textttr-help, suggesting they are motivated by the emphgamified environment. To our knowledge, our study is the first to directly chart the changes in behaviour of specific contributors as they migrate into gamified environments, and has important implications for knowledge management in software engineering.
Keywords: a; crowdsourced knowledge; gamification.; mailing lists; open source; social q&#38

How to Support Newcomers Onboarding to Open Source Software Projects - Steinmacher, Igor; Gerosa, MarcoAurélio (Open Source Software: Mobile Open Source Technologies, 2014)
While onboarding an open source software (OSS) project, contributors face many different barriers that hinder their contribution, leading in many cases to dropout. Many projects leverage the contribution of outsiders and the sustainability of the project relies on retaining some of these newcomers. In this research, we aim at understanding the barriers that hinder onboarding of newcomers to OSS projects, by means of different empirical approaches, and proposing a set of strategies that can be used to support the first step of newcomers.

How You Run a Meeting Says a Lot About Your Values: Participatory Practices for Open Communities - Thorne, Michelle (Proceedings of The International Symposium on Open Collaboration, 2014)
Live events are some of the best ways to see the power dynamics and philosophical bent of a community. Many communities, open and closed, glorify sitting in a darkened room and being inspired by a sage on the stage. And then there are events about participation: making and learning with fellow participants around shared passions and interests. The session argues for the use of participatory methods at events as a way to manifest open values. We'll unpack some techniques and case studies, as well as practice ourselves.

The Impact of Automatic Crash Reports on Bug Triaging and Development in Mozilla - Ahmed, Iftekhar; Mohan, Nitin; Jensen, Carlos (Proceedings of The International Symposium on Open Collaboration, 2014)
Free/Open Source Software projects often rely on users submitting bug reports. However, reports submitted by novice users may lack information critical to developers, and the process may be intimidating and difficult. To gather more and better data, projects deploy automatic crash reporting tools, which capture stack traces and memory dumps when a crash occurs. These systems potentially generate large volumes of data, which may overwhelm developers, and their presence may discourage users from submitting traditional bug reports. In this paper, we examine Mozilla's automatic crash reporting system and how it affects their bug triaging process. We find that fewer than 0.00009% of crash reports end up in a bug report, but as many as 2.33% of bug reports have data from crash reports added. Feedback from developers shows that despite some problems, these systems are valuable. We conclude with a discussion of the pros and cons of automatic crash reporting systems.
Keywords: Automatic Crash reporting; debugging; FOSS; Free/Open Source Software; Open Bug Reporting; testing

Impact of Collaboration on Structural Software Quality (Proceedings of The International Symposium on Open Collaboration, 2014)
The structural quality of a codebase is a key determining factor in the software's total cost of ownership, yet it is notoriously difficult to measure or predict. In this doctoral research we leverage the power of open source repositories to understand the factors that influence structural quality (and by extension fault-proneness) in the context of the patterns of collaborative behaviour exhibited by contributors. The objective is to further our understanding of how such behaviour impacts structural quality with the end goal being to inform management decision making across the industry in the pursuit of better software engineering practices.

Improving Mozilla’s In-App Payment Platform - Janczukowicz, Ewa; Bouabdallah, Ahmed; Braud, Arnaud; Fromentoux, Gaël; Bonnin, Jean-Marie (Open Source Software: Mobile Open Source Technologies, 2014)
Nowadays, an in-app payment mechanism is offered in most existing mobile payment solutions. However, current solutions are not flexible and impose certain restrictions: users are limited to predefined payment options and merchants need to adapt their payment mechanisms to each payment provider they use. Ideally mobile payments should be as flexible as possible to be able to target various markets together with users’ spending habits. Mozilla wants to promote an open approach in mobile payments by offering a flexible, easily accessible solution. This solution is analyzed, its shortcomings and possible improvements are discussed leading to an original proposal.

Industry Questions about Open Source Software in Business: Research Directions and Potential Answers - Ihara, Akinori; Monden, Akito; Matsumoto, Ken-ichi (2014 6th International Workshop on Empirical Software Engineering in Practice (IWESEP)2014 6th International Workshop on Empirical Software Engineering in Practice, 2014)
As open source software (OSS) has become an integral part of today's software businesses, many software companies rely on OSS to develop their customer solutions and products. On the other hand, they face various concerns in using OSS, such as technical support, quality, security and licensing issues. This paper focuses on OSS-related FAQ in industry, and tries to answer them or to provide research directions based on lessons learned from recent mining OSS repository researches.

Initial Results from the Study of the Open Source Sector in Belgium - Viseur, Robert (The International SymposiumProceedings of The International Symposium on Open Collaboration - OpenSym '14, 2014)
The economy of FLOSS (Free and open source software) has been the subject of numerous studies and publications, particularly on the issue of business models. However, there are fewer studies on the local networks of FLOSS providers. This research focuses on the ecosystem of Belgian FLOSS providers and, more specifically, their geographical distribution, the activities, technologies and software they support, their business models, their economic performance and the relationships between companies. The research is based on a directory containing nearly 150 companies. This directory led to the creation of a specialized search engine that helped to improve annotation. The research also uses financial data provided by the Belgian Central Balance Sheet Office. The initial results of this study show a concentration in major economic areas. The businesses are more active in the services and are heavily involved activities such as infrastructure software and Web development, activities which were common in the early years of free software development. Services for the support of business software is also common. A first analysis of the graph of relationships between providers' websites highlights the role that is played by the multinational IT companies, by FLOSS editors, by commercial FLOSS associations and especially by the Walloon centers of competence that offer vast training catalogs that are dedicated to FLOSS. This research opens up many perspectives for improving the automation of the company directory updates, the analysis of the relationship between enterprises, and the automation of the financial analysis of companies.

Innovation Diffusion in Open Source Software: Preliminary Analysis of Dependency Changes in the Gentoo Portage Package Database - Bloemen, Remco; Amrit, Chintan; Kuhlmann, Stefan; Ordóñez–Matamoros, Gonzalo (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
In this paper we make the case that software dependencies are a form of innovation adoption. We then test this on the time-evolution of the Gentoo package dependency graph. We find that the Bass model of innovation diffusion fits the growth of the number of packages depending on a given library. Interestingly, we also find that low-level packages have a primarily imitation driven adoption and multimedia libraries have primarily innovation driven growth.
Keywords: dependencies; gentoo; graph; INNOVATION

An Insight into the Pull Requests of GitHub - Rahman, Mohammad Masudur; Chanchal K. Roy (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
Given the increasing number of unsuccessful pull requests in GitHub projects, insights into the success and failure of these requests are essential for the developers. In this paper, we provide a comparative study between successful and unsuccessful pull requests made to 78 GitHub base projects by 20,142 developers from 103,192 forked projects. In the study, we analyze pull request discussion texts, project specific information (e.g., domain, maturity), and developer specific information (e.g., experience) in order to report useful insights, and use them to contrast between successful and unsuccessful pull requests. We believe our study will help developers overcome the issues with pull requests in GitHub, and project administrators with informed decision making.
Keywords: Commit comments; mining challenge; msr challenge; pull request; topic model

"The Institutionalization of Digital Openness" - Maximilian Heimstädt (The International SymposiumProceedings of The International Symposium on Open Collaboration - OpenSym '14, 2014)
Around the world national and municipal governments launch open data initiatives with declared goals like increased efficiency, transparency or economic growth. However, although little of these effects have been proven, more and more administrations open up their datasets to the public. The dissertation project describes this phenomenon as the ongoing institutionalization of digital openness in the field of public sector information. With empirical evidence from three case studies in large European cities the research project intends to theorize how NGOs, hackers and certain civil servants turn open data into an institution, which more and more public bodies feel the need to adapt to.

Investigating Social Media in GitHub's Pull-requests: A Case Study on Ruby on Rails - Zhang, Yang; Yin, Gang; Yu, Yue; Wang, Huaimin (Proceedings of the 1st International Workshop on Crowd-based Software Development Methods and Technologies, 2014)
In GitHub, pull-request mechanism is an outstanding social development method by integrating with many social media. Many studies have explored that social media has an important effect on software development. @-mention as a typical social media, is a useful tool in social platform. In this paper, we made a quantitative analysis of @-mention in pull-requests of the project Ruby on Rails. First, we make a convictive statistics of the popularity of pull-request mechanism in GitHub. Then we investigate the current situation of @-mention in the Ruby on Rails. Our empirical analysis results find some insights of @-mention.
Keywords: @-mention; github; pull-request; social media

It’s Not Only about Writing Code: An Investigation of the Notion of Citizenship Behaviors in the Context of Free/Libre/Open Source Software Communities - Carillo, Kevin Daniel Andre; Huff, Sid; Chawner, Brenda (47th International Hawai'i Conference on System Sciences (HICSS-47), 2014)
Attracting a large number of new contributors has been seen as a way to ensure the survival, long-term success, and sustainability of Free/Libre/Open Source Software (FLOSS) communities. However, this appears to be a necessary, but not a sufficient condition, as the well-being of FLOSS communities also relies on members behaving as “good citizens,” to nurture and protect the community. This paper investigates the notion of FLOSS community citizenship behaviors in light of the organizational citizenship behaviors literature. Relying on 11 semi-structured interviews with FLOSS project leaders and community managers, the papers identifies key instances of citizenship behaviors along two dimensions: CCB-I (community citizenship behaviors oriented towards the benefits of other individuals), and CCB-P (community citizenship behaviors oriented towards the benefits of the project and its community).

A Layered Approach to Managing Risks in OSS Projects - Franch, Xavier; Kenett, Ron; Mancinelli, Fabio; Susi, Angelo; Ameller, David; Ben-Jacob, Ron; Siena, Alberto (Open Source Software: Mobile Open Source Technologies, 2014)
In this paper, we propose a layered approach to managing risks in OSS projects. We define three layers: the first one for defining risk drivers by collecting and summarising available data from different data sources, including human-provided contextual information; the second layer, for converting these risk drivers into risk indicators; the third layer for assessing how these indicators impact the business of the adopting organisation. The contributions are: 1) the complexity of gathering data is isolated in one layer using appropriate techniques, 2) the context needed to interpret this data is provided by expert involvement evaluating risk scenarios and answering questionnaires in a second layer, 3) a pattern-based approach and risk reasoning techniques to link risks to business goals is proposed in the third layer.
Keywords: Layered Model; open source; OSS; Risk Management

Lean GHTorrent: GitHub Data on Demand - Gousios, Georgios; Vasilescu, Bogdan; Serebrenik, Alexander; Zaidman, Andy (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
In recent years, GitHub has become the largest code host in the world, with more than 5M developers collaborating across 10M repositories. Numerous popular open source projects (such as Ruby on Rails, Homebrew, Bootstrap, Django or jQuery) have chosen GitHub as their host and have migrated their code base to it. GitHub offers a tremendous research potential. For instance, it is a flagship for current open source development, a place for developers to showcase their expertise to peers or potential recruiters, and the platform where social coding features or pull requests emerged. However, GitHub data is, to date, largely underexplored. To facilitate studies of GitHub, we have created GHTorrent, a scalable, queriable, offline mirror of the data offered through the GitHub REST API. In this paper we present a novel feature of GHTorrent designed to offer customisable data dumps on demand. The new GHTorrent data-on-demand service offers users the possibility to request via a web form up-to-date GHTorrent data dumps for any collection of GitHub repositories. We hope that by offering customisable GHTorrent data dumps we will not only lower the "barrier for entry" even further for researchers interested in mining GitHub data (thus encourage researchers to intensify their mining efforts), but also enhance the replicability of GitHub studies (since a snapshot of the data on which the results were obtained can now easily accompany each study).
Keywords: data on demand; dataset; github; msr data showcase

Lessons Learned from Teaching Open Source Software Development - Morgan, Becka; Jensen, Carlos (Open Source Software: Mobile Open Source Technologies, 2014)
Free/Open Source Software allows students to learn valuable real world skills and experiences, as well as a create a portfolio to show future employers. However, the learning curve to joining FOSS can be daunting, often leading newcomers to walk away frustrated. Universities therefore need to find ways to provide a structured introduction to students, helping them overcome the barriers to entry. This paper describes two courses taught at two universities, built around a Communities of Practice model, and the lessons learned from these. Suggestions and insights are shared for how to structure and evaluate such courses for maximum effect.
Keywords: education; FOSS; Free/Open Source Software

Magnet or Sticky? An OSS Project-by-project Typology - Yamashita, Kazuhiro; McIntosh, Shane; Kamei, Yasutaka; Ubayashi, Naoyasu (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
For Open Source Software (OSS) projects, retaining existing contributors and attracting new ones is a major concern. In this paper, we expand and adapt a pair of population migration metrics to analyze migration trends in a collection of open source projects. Namely, we study: (1) project stickiness, i.e., its tendency to retain existing contributors and (2) project magnetism, i.e., its tendency to attract new contributors. Using quadrant plots, we classify projects as attractive (highly magnetic and sticky), stagnant (highly sticky, weakly magnetic), fluctuating (highly magnetic, weakly sticky), or terminal (weakly magnetic and sticky). Through analysis of the MSR challenge dataset, we find that: (1) quadrant plots can effectively identify at-risk projects, (2) stickiness is often motivated by professional activity and (3) transitions among quadrants as a project ages often coincides with interesting events in the evolution history of a project.
Keywords: Developer migration; Magnet; mining challenge; msr challenge; open source; Sticky

"May the fork be with you": novel metrics to analyze collaboration on GitHub - Marco Biazzini; Benoit Baudry (Proceedings of the 5th International Workshop on Emerging Trends in Software Metrics - WETSoM 2014, 2014)
Multi–repository software projects are becoming more and more popular, thanks to web–based facilities such as GitHub. Code and process metrics generally assume a single repository must be analyzed, in order to measure the characteristics of a codebase. Thus they are not apt to measure how much relevant information is hosted in multiple repositories contributing to the same codebase. Nor can they feature the characteristics of such a distributed development process. We present a set of novel metrics, based on an original classification of commits, conceived to capture some interesting aspects of a multi–repository development process. We also describe an efficient way to build a data structure that allows to compute these metrics on a set of Git repositories. Interesting outcomes, obtained by applying our metrics on a large sample of projects hosted on GitHub, show the usefulness of our contribution.
Keywords: flossmole; github

Measuring the Health of Open Source Software Ecosystems: Moving Beyond the Scope of Project Health - Slinger Jansen (2014)
Background. The livelihood of an open source ecosystem is important to different ecosystem participants: software developers, end-users, investors, and participants want to know whether their ecosystem is healthy and performing well. Currently, there exists no working operationalization available that can be used to determine the health of open source ecosystems. Health is typically looked at from a project scope, not from an ecosystem scope. Objectives. With such an operationalization, stakeholders can make better decisions on whether to invest in an ecosystem: developers can select the healthiest ecosystem to join, keystone organizers can establish which governance techniques are effective, and end-users can select ecosystems that are robust, will live long, and prosper. Method. Design research is used to create the health operationalization. The evaluation step is done using four ecosystem health projects from literature. Results. The Open Source Ecosystem Health Operationalization is provided, which establishes the health of a complete software ecosystem, using the data from collections of open source projects that belong to the ecosystem. Conclusion. The groundwork is done, by providing a summary of research challenges, for more research in ecosystem health. With the operationalization in hand, re- searchers no longer need to start from scratch when researching open source ecosystems’ health.
Keywords: open source ecosystems; Software ecosystem health; Software repository mining

The Merits of a Meritocracy in Open Source Software Ecosystems - Eckhardt, Evert; Kaats, Erwin; Slinger Jansen; Alves, Carina (Proceedings of the 2014 European Conference on Software Architecture Workshops, 2014)
The Eclipse open source ecosystem has grown from a small internal IBM project to one of the biggest Integrated Development Environments in the market. Open source communities and ecosystems do not follow the standard governance strategies typically used in large organizations. A meritocracy is a frequently occurring form of governance on different levels in open ecosystems. In this paper we investigate how this form of governance influences the health of projects within the Eclipse ecosystem in terms of the amount of commits within each month. We analyzed the hierarchy of Eclipse, how merits are conceptualized within the ecosystem and the effect of the appointments of mentors and project leads on the amount of commits. From our research, we can conclude that this system is not always as fair as it seems; merits are only a benefit in some cases.
Keywords: Ecosystem Health; Meritocracy; open source; Software ecosystems

A Methodology for Managing FOSS Migration Projects - Goñi, Angel; Boodraj, Maheshwar; Cabreja, Yordanis (Open Source Software: Mobile Open Source Technologies, 2014)
Since 2005, the Free Software Center (CESOL) at the University of Information Science (UCI) in Havana, Cuba, has conducted several free and open source software (FOSS) migration projects for various organizations. The experience gained from these projects enabled the creation of a FOSS Migration Methodology which documented how the technical elements of a project of this kind should be executed. Despite the usefulness of this methodology, the projects that have been undertaken experienced difficulties that were, in most cases, directly related to their management. This research aims to improve the methodology and minimize management-related challenges thereby improving the quality of migration projects. The proposed methodology was applied in a project that ran in a higher education organization and the results prove that the methodology enhanced the quality of the migration project.

Microblogging in Open Source Software Development: The Case of Drupal and Twitter - Wang, Xiaofang; Kuzmickaja, Ilona; Stol, Klaas-Jan; Abrahamsson, Pekka; Fitzgerald, Brian (IEEE Software, 2014)
Microblogging is a popular form of social media that has quickly permeated both enterprise and open source communities. However, exactly how open source communities can leverage microblogging isn't yet well understood. The authors investigate how Drupal's open source community uses Twitter, a household name in microblogging. Their analysis of group and individual accounts of Drupal developers reveals that they take on similar but distinct roles. Both serve as communicators of essential links to a vast and growing community knowledge base, such as work artifacts, issues, documentation, and blog posts, but community members often express positive emotions when tweeting about work, which reinforces a sense of community.

MODELING DISTRIBUTED COLLABORATION ON GITHUB - McDONALD, NORA; Blincoe, Kelly; PETAKOVIC, EVA; Goggins, Sean (Advances in Complex Systems, 2014)
In this paper, we apply concepts from Distributed Leadership, a theory suggesting that leadership is shared among members of an organization, to frame models of contribution that we uncover in five relatively successful open source software (OSS) projects hosted on GitHub. In this qualitative, comparative case study, we show how these projects make use of GitHub features such as pull requests (PRs). We find that projects in which member PRs are more frequently merged with the codebase experience more sustained participation. We also find that projects with higher success rates among contributors and higher contributor retention tend to have more distributed (non-centralized) practices for reviewing and processing PRs. The relationships between organizational form and GitHub practices are enabled and made visible as a result of GitHub's novel interface. Our results demonstrate specific dimensions along which these projects differ and explicate a framework that warrants testing in future studies of OSS, particularly GitHub.

Models of OSS Project Meta-information: A Dataset of Three Forges - Williams, James R.; Di Ruscio, Davide; Matragkas, Nicholas; Di Rocco, Juri; Kolovos, Dimitris S. (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
The process of selecting open-source software (OSS) for adoption is not straightforward as it involves exploring various sources of information to determine the quality, maturity, activity, and user support of each project. In the context of the OSSMETER project, we have developed a forge-agnostic metamodel that captures the meta-information common to all OSS projects. We specialise this metamodel for popular OSS forges in order to capture forge-specific meta-information. In this paper we present a dataset conforming to these metamodels for over 500,000 OSS projects hosted on three popular OSS forges: Eclipse, SourceForge, and GitHub. The dataset enables different kinds of automatic analysis and supports objective comparisons of cross-forge OSS alternatives with respect to a user's needs and quality requirements.
Keywords: data mining; flossmole cited

Modern Code Reviews in Open-source Projects: Which Problems Do They Fix? - Beller, Moritz; Bacchelli, Alberto; Zaidman, Andy; Juergens, Elmar (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
Code review is the manual assessment of source code by humans, mainly intended to identify defects and quality problems. Modern Code Review (MCR), a lightweight variant of the code inspections investigated since the 1970s, prevails today both in industry and open-source software (OSS) systems. The objective of this paper is to increase our understanding of the practical benefits that the MCR process produces on reviewed source code. To that end, we empirically explore the problems fixed through MCR in OSS systems. We manually classified over 1,400 changes taking place in reviewed code from two OSS projects into a validated categorization scheme. Surprisingly, results show that the types of changes due to the MCR process in OSS are strikingly similar to those in the industry and academic systems from literature, featuring the similar 75:25 ratio of maintainability-related to functional problems. We also reveal that 7–35% of review comments are discarded and that 10–22% of the changes are not triggered by an explicit review comment. Patterns emerged in the review data; we investigated them revealing the technical factors that influence the number of changes due to the MCR process. We found that bug-fixing tasks lead to fewer changes and tasks with more altered files and a higher code churn have more changes. Contrary to intuition, the person of the reviewer had no impact on the number of changes.
Keywords: code review; defects; open source software

Navigation Support in Evolving Open-Source Communities by a Web-Based Dashboard - Hannemann, Anna; Liiva, Kristjan; Klamma, Ralf (Open Source Software: Mobile Open Source Technologies, 2014)
The co-evolution of communities and systems in open-source software (OSS) projects is an established research topic. There are plenty of different studies of OSS community and system evolution available. However, most of the existing OSS project visualization tools provide source code oriented metrics with little support for communities. At the same time, self-reflection helps OSS community members to understand what is happening within their community. Considering missing community-centered OSS visualizations, we investigated the following research question: Are the OSS communities interested in a visualization platform, which reflects community evolution? If so, what aspects should it reflect? To answer this research question, we first conducted an online survey within different successful OSS communities. The results of our evaluation showed that there is a great interest in community-centered statistics. Therefore, we developed an OSS navigator: a Web-based dashboard for community-oriented reflection of OSS projects. The navigator was filled with data from communication and development repositories of three large bioinformatics OSS projects. The members of these OSS communities tested the prototype. The bioinformatics OSS developers acknowledged the uniqueness of statistics that the NOSE dashboard offers. Especially, graph visualization of the project social network received the highest attention. This network view combined with other community-oriented metrics can significantly enhance the existing visualizations or even be provided as a standalone tool.

OCData Hackathon @ CSCW 2014 - Goggins, Sean; Andrea Wiggins; Susan Winter; Brian Butler (Proceedings of the 17th ACM conference on Computer supported cooperative work & social computing, 2014)
Online Communities data is prevalent in CSCW research, but the approaches to collecting, managing, analyzing and visualizing large scale social data varies on a lab by lab basis. The OCData hackathon is aimed at creating a community opportunity to share approaches to online communities research at the level of data. Integrating data, tools and theories to address interesting research questions remains a challenge for the community.

Older Adults and Free/Open Source Software - Davidson, Jennifer; Umme Ayda Mannan; Rithika Naik; Ishneet Dua; Jensen, Carlos (The International SymposiumProceedings of The International Symposium on Open Collaboration - OpenSym '14, 2014)
The global population is aging rapidly, and older adults are becoming increasingly technically savvy. This paper explores ways to engage these individuals to contribute to free/open source software (FOSS) projects. We conducted a pilot diary study to explore motivations, barriers, and the contribution processes of first-time contributors in a real time, qualitative manner. In addition, we measured their self-efficacy before and after their participation. We found that what drove participants were intrinsic motivations, altruism, and internal values, which differed from previous work with older adults and with the general FOSS population. We also found that self-efficacy did not change significantly, even when participants encountered significant barriers or setbacks. The top 3 barriers were lack of communication, installation issues, and documentation issues. We found that asking for and receiving help, and avoiding difficult development environments were more likely to lead to success. To verify these results, we encourage a future large-scale diary study that involves multiple demographics. Given our pilot study, we recommend that future outreach efforts involving older adults focus on how to effectively communicate and build community amongst older contributors.

Oops! Where Did That Code Snippet Come from? - Guo, Lisong; Lawall, Julia; Muller, Gilles (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
A kernel oops is an error report that logs the status of the Linux kernel at the time of a crash. Such a report can provide valuable first-hand information for a Linux kernel maintainer to conduct postmortem debugging. Recently, a repository has been created that systematically collects kernel oopses from Linux users. However, debugging based on only the information in a kernel oops is difficult. We consider the initial problem of finding the offending line, i.e., the line of source code that incurs the crash. For this, we propose a novel algorithm based on approximate sequence matching, as used in bioinformatics, to automatically pinpoint the offending line based on information about nearby machine-code instructions, as found in a kernel oops. Our algorithm achieves 92% accuracy compared to 26% for the traditional approach of using only the oops instruction pointer.
Keywords: debugging; linux kernel; oops; sequence alignment

Open Source Mobile Virtual Machines: An Energy Assessment of Dalvik vs. ART - Georgiev, AntonB.; Sillitti, Alberto; Succi, Giancarlo (Open Source Software: Mobile Open Source Technologies, 2014)
Dalvik Virtual Machine is Open Source Software and an important part of the Android OS and its better understanding and energy optimization can significantly contribute to the overall greenness of the mobile environment. With the introduction of the OSS solution, named Android Runtime (ART) an attempt of performance and energy consumption optimization was made. In this paper we investigate and compare the performance of the Dalvik virtual and ART from energy perspective. In order to answer our research questions we executed a set of benchmarks in identical experimental setup for both runtimes, while measuring the energy spent and percentage of battery discharge. The results showed that in most of the use case scenarios Ahead-Of-Time compilation process of ART is overall more energy efficient than the Just-In- Time one of Dalvik.

OpenHub: A Scalable Architecture for the Analysis of Software Quality Attributes - Farah, Gabriel; Tejada, Juan Sebastian; Correal, Dario (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
There is currently a vast array of open source projects available on the web, and although they are searchable by name or description in the search engines, there is no way to search for projects by how well they perform on a given set of quality attributes (e.g. usability or maintainability). With OpenHub, we present a scalable and extensible architecture for the static and runtime analysis of open source repositories written in Python, presenting the architecture and pinpointing future possibilities with it.
Keywords: architecture; github; python; Quality Attributes

Opening up to open source: looking at how Moodle was adopted in higher education - Costello, Eamon (Open Learning: The Journal of Open, Distance and e-Learning, 2014)
The Virtual Learning Environment (VLE) has grown to become a piece of complex infrastructure that is now deemed to be critical to higher educational provision. This paper looks at Moodle and its adoption in higher education. Moodle’s origins, as an open source VLE, are investigated and its growth examined in the context of how higher educational institutions adopt VLEs.

Open-Source Software Entrepreneurial Business Modelling - Teixeira, Jose; Salminen, Joni (Open Source Software: Mobile Open Source Technologies, 2014)
This poster aims to facilitate business planning of bootstrapping entrepreneurs who are developing a high-tech business by open-source approach. It draws on scholarly works on business modelling and open-source software to provide a practical tool for entrepreneurs establishing a business by open-source approach. Built on top of established business modelling frameworks, the Open-Source Software Entrepreneurial Business Modelling (OSS_EBM) can be a useful strategic management and entrepreneurial tool. It enables strategists and entrepreneurs to describe, design, challenge, invent, brainstorm, pivot, analyze and improve upon open-source business models.

PAID VS. VOLUNTEER WORK IN OPEN SOURCE - Dirk Riehle; Riemer, Philipp; Carsten Kolassa; Michael Schmidt (47th International Hawai'i Conference on System Sciences (HICSS-47), 2014)
Many open source projects have long become commercial. This paper shows just how much of open source software development is paid work and how much has remained volunteer work. Using a conservative approach, we find that about 50% of all open source software development has been paid work for many years now and that many small projects are fully paid for by companies. However, we also find that any non-trivial project balances the amount of paid developer with volunteer work, and we suggest that the ratio of volunteer to paid work can serve as an indicator for the health of open source projects and aid the management of the respective communities.

A Performance Analysis of Wireless Mesh Networks Implementations Based on Open Source Software - Armuelles Voinov, Iván; Cedeño, AidelenChung; Chung, Joaquín; González, Grace (Open Source Software: Mobile Open Source Technologies, 2014)
Wireless mesh networks (WMNs) have emerged as a promising technology, capable of provide broadband connectivity at low cost. Implementations based on Open Source Software of these networks offer advantages for providing broadband networking communications in scenarios where cabling is too expensive or prohibitive such as rural environments. In this paper we evaluate the performance of small scale wireless mesh WMN routing protocols for WMNs: B.A.T.M.A.N. Advanced and the 802.11s standard. We also compare an OpenFlow controller implemented over the WMN, verifying their bandwidth, datagram loss and jitter.
Keywords: network performance; Open Source Software for research and innovation; OpenFlow; OpenWRT; Wireless Mesh Networks

Polytrix: A Pacto-Powered Polyglot Test Matrix - Lincoln, Max; Alves, Fernando (Open Source Software: Mobile Open Source Technologies, 2014)
We have created a polyglot test framework named Polytrix to compare, benchmark, and independently verify a suite of open-source OpenStack SDKs that each target a different programming language. The framework validates sample code from each SDK against a shared test scenario to validate that each SDK correctly implements a given scenario. It uses Pacto for integration contract testing between the SDKs and the OpenStack services, and generates test reports that help compare and document each SDK. It is designed so interactive training materials can be generated in future versions.

PROINFODATA: Monitoring a Large Park of Computational Laboratories - Possamai, CleideL.B.; Pasqualin, Diego; Weingaertner, Daniel; Todt, Eduardo; Castilho, MarcosA.; Bona, LuisC.E.; Almeida, EduardoCunha (Open Source Software: Mobile Open Source Technologies, 2014)
This paper briefly presents a model for monitoring a large, heterogeneous and geographically scattered computer park. The data collection is performed by a software agent. The collected data are sent to the central server over the Internet, and stored by the storage system. An on-line portal makes up the visualization system, featuring charts, reports, and other tools for assessing the state of the park. This system is currently monitoring circa 150,000 machines.

The Promises and Perils of Mining GitHub - Kalliamvakou, Eirini; Gousios, Georgios; Blincoe, Kelly; Singer, Leif; Daniel M. German; Damian, Daniela (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
With over 10 million git repositories, GitHub is becoming one of the most important source of software artifacts on the Internet. Researchers are starting to mine the information stored in GitHub's event logs, trying to understand how its users employ the site to collaborate on software. However, so far there have been no studies describing the quality and properties of the data available from GitHub. We document the results of an empirical study aimed at understanding the characteristics of the repositories in GitHub and how users take advantage of GitHub's main features---namely commits, pull requests, and issues. Our results indicate that, while GitHub is a rich source of data on software development, mining GitHub for research purposes should take various potential perils into consideration. We show, for example, that the majority of the projects are personal and inactive; that GitHub is also being used for free storage and as a Web hosting service; and that almost 40% of all pull requests do not appear as merged, even though they were. We provide a set of recommendations for software engineering researchers on how to approach the data in GitHub.
Keywords: bias; code reviews; git; github; mining software repositories

Recommending relevant projects via user behaviour: an exploratory study on github - Zhang, Lingxiao; Yanzhen Zou; Bing Xie; Zixiao Zhu (Proceedings of the 1st International Workshop on Crowd-based Software Development Methods and Technologies - CrowdSoft 2014, 2014)
Social coding sites (e.g., Github) provide various features like Forking and Sending Pull-requests to support crowd-based software engineering. When using these features, a large amount of user behavior data is recorded. User behavior data can reflect developers preferences and interests in software development activities. Online service providers in many fields have been using user behavior data to discover user preferences and interests to achieve various purposes. In the field of software engineering however, there has been few studies in mining large amount of user behavior data. Our goal is to design an approach based on user behavior data, to recommend relevant open source projects to developers, which can be helpful in activities like searching for the right open source solutions to quickly build prototypes. In this paper, we explore the possibilities of such a method by conducting a set of experiments on selected data sets from Github. We find it a promising direction in mining projects' relevance from user behavior data. Our study also obtain some important issues that is worth considering in this method.

Security and Emotion: Sentiment Analysis of Security Discussions on GitHub - Pletea, Daniel; Vasilescu, Bogdan; Serebrenik, Alexander (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
Application security is becoming increasingly prevalent during software and especially web application development. Consequently, countermeasures are continuously being discussed and built into applications, with the goal of reducing the risk that unauthorized code will be able to access, steal, modify, or delete sensitive data. In this paper we gauged the presence and atmosphere surrounding security-related discussions on GitHub, as mined from discussions around commits and pull requests. First, we found that security related discussions account for approximately 10% of all discussions on GitHub. Second, we found that more negative emotions are expressed in security-related discussions than in other discussions. These findings confirm the importance of properly training developers to address security concerns in their applications as well as the need to test applications thoroughly for security vulnerabilities in order to reduce frustration and improve overall project atmosphere.
Keywords: github; mining challenge; msr challenge; security; sentiment analysis

Sentiment Analysis of Commit Comments in GitHub: An Empirical Study - Guzman, Emitza; Azócar, David; Li, Yang (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
Emotions have a high impact in productivity, task quality, creativity, group rapport and job satisfaction. In this work we use lexical sentiment analysis to study emotions expressed in commit comments of different open source projects and analyze their relationship with different factors such as used programming language, time and day of the week in which the commit was made, team distribution and project approval. Our results show that projects developed in Java tend to have more negative commit comments, and that projects that have more distributed teams tend to have a higher positive polarity in their emotional content. Additionally, we found that commit comments written on Mondays tend to a more negative emotion. While our results need to be confirmed by a more representative sample they are an initial step into the study of emotions and related factors in open source projects.
Keywords: Human Factors in Software Engineering; mining challenge; msr challenge; sentiment analysis

SENTIMENT ANALYSIS OF FREE/OPEN SOURCE DEVELOPERS: PRELIMINARY FINDINGS FROM A CASE STUDY - Rousinopoulos, Athanasios-Ilias; Gregorio Robles; González-Barahona, Jesús M. (Revista Eletrônica de Sistemas de Informação, 2014)
Software development is a human intensive activity. And as such, how developers face their tasks is of major importance. In an environment such as the one that is common in FOSS (free/open source software) projects where professionals (i.e., paid developers) share the development effort with volunteers, the morale of the development and user community is of major importance. In this paper, we present a preliminary analysis using sentiment analysis techniques to a FOSS project. We therefore mine the mailing list of a project and apply these techniques to the most relevant participants. Although the application is at this time limited, we hope that this experience can be of benefit in the future to determine situations that may affect the developers or the project, such as low productivity, developer abandonment, project forking, etc.
Keywords: developer productivity; FLOSS; mailing lists; natural language processing; openSUSE; sentiment analysis; software development; software repository mining

The Small World Network Effect in Software Project Teams - Kevin Peterson (2014)
Team cohesion and the dynamics of team formation are important parts of any project, with software projects being no exception. An interesting aspect of team building is the relationships formed between the team members. Because of these relationships, representing software team members as a graph may be a natural way to explore team dynamics. As team members move between projects, these graphs be- come more and more connected as team members col- laborate and form new relationships. We show that this connectivity, known as the “small world effect,” has a positive impact on team performance when the connectivity levels are moderate. Performance de- grades, however, at both very high and very low lev- els of connectivity. This aligns with similar research findings of non-software teams.
Keywords: flossmole

Smart TV with Free Technologies in Support of Teaching-Learning Process - Rosales Rosa, Eugenio; Fírvida Donéstevez, AbelAlfonso; González Muño, Marielis; Fuentes, AllanPierra (Open Source Software: Mobile Open Source Technologies, 2014)
The digital divide created between Cuba and the rest of the world has forced us to use alternative technologies in order to preserve and strengthen the achievements of the Revolution in the field of education. One of the actions undertaken in this regard consists of making audiovisual equipment and media become a supplementary element of the teacher’s educational work, and thus ensuring the rational use of the aforesaid media. This paper shows how to use a new trend of information technology and communications, using hybrid or smart TVs. This low-cost solution for low energy consumption, conceived as part of the educational process at all levels of the Island, provides some technical aspects and also shows, in the outline, some other ideas for incorporating this technology into the teaching-learning process. The results of laboratory tests are likewise shown.

Social aspects of collaboration in online software communities - Vasilescu, Bogdan (2014)
Software engineering is inherently a collaborative venture, involving many stakeholders that coordinate their efforts to produce large software systems. In distributed (online) settings, endemic to open-source software (OSS) development, such collaborations span geographies and cultures. Contributors with different skill sets, personalities, cultural backgrounds, or geographic locations self-organise in online software communities and voluntarily contribute to a collaborative effort, such as developing and evolving software systems, offering user support, or sharing knowledge. Myriads of online software communities exist. Among the most visible are those around the Linux operating system and its various distributions, the Gnome desktop environment, the Apache or Mozilla software foundations or, more recently, the GitHub repository hosting platform, or the Stack Exchange network of question and answer sites (e.g., Stack Overflow for programming-related questions). Different communities operate by different rules and offer different incentives to contribute. More traditional communities such as Gnome or Apache rely mostly on the intrinsic motivations of developers. In contrast, younger communities offer social media and gamification features (e.g., contributors to Stack Overflow are rewarded for their activity with reputation points and badges) as well as increased visibility to peers (e.g., the activity and achievements of GitHub and Stack Overflow contributors are aggregated and displayed on public profile pages). Furthermore, online software communities are often interdependent. For example, a Gnome contributor may engage simultaneously in different communities part of the Gnome ecosystem, where she may take on different roles or instead choose to specialise in similar tasks. Similarly, a GitHub contributor may participate simultaneously in Stack Overflow, where she may seek help from peers or instead share her knowledge and expertise to help educate others. Starting from the recent realisation of the empirical software engineering research community that social aspects are at least as important for the success of distributed collaborations as technical ones, this dissertation is an attempt to understand collaboration in representative online software communities from a social perspective. To this end, we mines and analyses a wealth of publicly available trace data using state-of-the-art statistical techniques, from various standpoints outlined below. The work in this dissertation sits at the intersection of two research communities, computer-supported cooperative work (CSCW) and software engineering (SE). Consequently, it offers contributions to both SE and CSCW, ranging from methods and tools to mine and analyse large amounts of (social) trace data, to practical implications for software maintainability, software team management, knowledge management or community design. First, we propose individual-level measures of workload, involvement, and specialisation of labour in online software development communities, and report on a case study of the Gnome ecosystem community. Additionally, we propose a community-level measure of skill diversity with respect to a certain technical skill, such as knowledge of a given programming language. Social interactions between contributors to software development communities and their degree of participation have been reported repeatedly to influence software quality and complexity. Similarly, skill heterogeneity in a software community is important for the community’s survival and performance. Second, we analyse the effects of simultaneously contributing to multiple communities on individual working rhythms. We focus on developers contributing source code to GitHub repositories while seeking and sharing knowledge on Stack Overflow. Despite the popularity of Stack Overflow, its role in the work cycle of OSS developers is yet to be understood. On the one hand, participation in it has the potential to increase the knowledge of individual developers thus improving and speeding up the development process. On the other hand, participation in Stack Overflow may interrupt the regular working rhythm of a developer, hence also possibly slow down the development process. We show that active GitHub contributors typically engage in Stack Overflow as experts, asking few questions and providing many answers for others. Moreover, despite the interruptions incurred, the Stack Overflow activity rate correlates with the code changing rate on GitHub. Third, we chart the changes in behaviour of contributors to online knowledge sharing communities as they migrate into gamified environments. To this end, we assemble a joint data set for R (a widely-used tool for data analysis) by integrating data from mailing lists and Stack Exchange sites, having activities of individual contributors linked across the two resources and also over time. We find that user support activities show a strong shift away from mailing lists (historically the hub for development and user support activities in online software communities) and towards Stack Exchange. Moreover, knowledge providers contributing to both communities provide faster answers on Stack Exchange than on the mailing list, and their total output increases after the transition. Fourth, we revisit the gamified Stack Overflow environment from the perspectives of gender representation and participation patterns, in comparison to traditional information sharing venues such as mailing lists. In addition to encouraging competitiveness through its gamification features, anecdotal evidence around Stack Overflow suggests that it is an unfriendly community that promotes one-upmanship, or fosters flame-wars and the down-voting of individuals. We find that while women are under-represented in all studied communities, they show different participation patterns on Stack Overflow, where they disengage sooner than men. However, relative to the duration of their engagement in the community, women on Stack Overflow are at least as active as men. Fifth, we address the recurring mining software repositories challenge of inconsistent identity data. To this end, we analyse the robustness of two representative existing identity merging algorithms with respect to different types of noise typical of software repositories, and we propose a new identity merging algorithm inspired by Latent Semantic Analysis, a popular information retrieval technique expected to perform well in presence of noise. Using data extracted from Gnome Git repositories, we evaluate the performance of our algorithm empirically by means of cross-validation, and show an improvement over existing approaches in terms of precision and recall on worst-case input data. Last, we provide an example of the applicability of methods developed or refined as part of this work beyond online software communities. Specifically, we propose a metrics suite to study the health of software engineering conferences and conference communities, measuring such attributes as stability, openness to new authors, or introversion. Using this metrics suite, we assess the health of 11 established software engineering conferences over a period of more than 10 years. In general, we find that software engineering conferences are healthy, with some notable differences depending on the chosen health metric, or a conference’s wide or narrow scope. Beyond demonstrating the generalisability of our techniques, this latter study has implications for conference steering committees or program committee chairs wishing to assess their selection process, or prospective authors trying to decide in which conferences to publish.

Social aspects of collaboration in online software communities (2014)
Software engineering is inherently a collaborative venture, involving many stakeholders that coordinate their efforts to produce large software systems. In distributed (online) settings, endemic to open-source software (OSS) development, such collaborations span geographies and cultures. Contributors with different skill sets, personalities, cultural backgrounds, or geographic locations self-organise in online software communities and voluntarily contribute to a collaborative effort, such as developing and evolving software systems, offering user support, or sharing knowledge. Myriads of online software communities exist. Among the most visible are those around the Linux operating system and its various distributions, the Gnome desktop environment, the Apache or Mozilla software foundations or, more recently, the GitHub repository hosting platform, or the Stack Exchange network of question and answer sites (e.g., Stack Overflow for programming-related questions). Different communities operate by different rules and offer different incentives to contribute. More traditional communities such as Gnome or Apache rely mostly on the intrinsic motivations of developers. In contrast, younger communities offer social media and gamification features (e.g., contributors to Stack Overflow are rewarded for their activity with reputation points and badges) as well as increased visibility to peers (e.g., the activity and achievements of GitHub and Stack Overflow contributors are aggregated and displayed on public profile pages). Furthermore, online software communities are often interdependent. For example, a Gnome contributor may engage simultaneously in different communities part of the Gnome ecosystem, where she may take on different roles or instead choose to specialise in similar tasks. Similarly, a GitHub contributor may participate simultaneously in Stack Overflow, where she may seek help from peers or instead share her knowledge and expertise to help educate others. Starting from the recent realisation of the empirical software engineering research community that social aspects are at least as important for the success of distributed collaborations as technical ones, this dissertation is an attempt to understand collaboration in representative online software communities from a social perspective. To this end, we mines and analyses a wealth of publicly available trace data using state-of-the-art statistical techniques, from various standpoints outlined below. The work in this dissertation sits at the intersection of two research communities, computer-supported cooperative work (CSCW) and software engineering (SE). Consequently, it offers contributions to both SE and CSCW, ranging from methods and tools to mine and analyse large amounts of (social) trace data, to practical implications for software maintainability, software team management, knowledge management or community design. First, we propose individual-level measures of workload, involvement, and specialisation of labour in online software development communities, and report on a case study of the Gnome ecosystem community. Additionally, we propose a community-level measure of skill diversity with respect to a certain technical skill, such as knowledge of a given programming language. Social interactions between contributors to software development communities and their degree of participation have been reported repeatedly to influence software quality and complexity. Similarly, skill heterogeneity in a software community is important for the community’s survival and performance. Second, we analyse the effects of simultaneously contributing to multiple communities on individual working rhythms. We focus on developers contributing source code to GitHub repositories while seeking and sharing knowledge on Stack Overflow. Despite the popularity of Stack Overflow, its role in the work cycle of OSS developers is yet to be understood. On the one hand, participation in it has the potential to increase the knowledge of individual developers thus improving and speeding up the development process. On the other hand, participation in Stack Overflow may interrupt the regular working rhythm of a developer, hence also possibly slow down the development process. We show that active GitHub contributors typically engage in Stack Overflow as experts, asking few questions and providing many answers for others. Moreover, despite the interruptions incurred, the Stack Overflow activity rate correlates with the code changing rate on GitHub. Third, we chart the changes in behaviour of contributors to online knowledge sharing communities as they migrate into gamified environments. To this end, we assemble a joint data set for R (a widely-used tool for data analysis) by integrating data from mailing lists and Stack Exchange sites, having activities of individual contributors linked across the two resources and also over time. We find that user support activities show a strong shift away from mailing lists (historically the hub for development and user support activities in online software communities) and towards Stack Exchange. Moreover, knowledge providers contributing to both communities provide faster answers on Stack Exchange than on the mailing list, and their total output increases after the transition. Fourth, we revisit the gamified Stack Overflow environment from the perspectives of gender representation and participation patterns, in comparison to traditional information sharing venues such as mailing lists. In addition to encouraging competitiveness through its gamification features, anecdotal evidence around Stack Overflow suggests that it is an unfriendly community that promotes one-upmanship, or fosters flame-wars and the down-voting of individuals. We find that while women are under-represented in all studied communities, they show different participation patterns on Stack Overflow, where they disengage sooner than men. However, relative to the duration of their engagement in the community, women on Stack Overflow are at least as active as men. Fifth, we address the recurring mining software repositories challenge of inconsistent identity data. To this end, we analyse the robustness of two representative existing identity merging algorithms with respect to different types of noise typical of software repositories, and we propose a new identity merging algorithm inspired by Latent Semantic Analysis, a popular information retrieval technique expected to perform well in presence of noise. Using data extracted from Gnome Git repositories, we evaluate the performance of our algorithm empirically by means of cross-validation, and show an improvement over existing approaches in terms of precision and recall on worst-case input data. Last, we provide an example of the applicability of methods developed or refined as part of this work beyond online software communities. Specifically, we propose a metrics suite to study the health of software engineering conferences and conference communities, measuring such attributes as stability, openness to new authors, or introversion. Using this metrics suite, we assess the health of 11 established software engineering conferences over a period of more than 10 years. In general, we find that software engineering conferences are healthy, with some notable differences depending on the chosen health metric, or a conference’s wide or narrow scope. Beyond demonstrating the generalisability of our techniques, this latter study has implications for conference steering committees or program committee chairs wishing to assess their selection process, or prospective authors trying to decide in which conferences to publish.

Socio-Technical Congruence in the Ruby Ecosystem - Syeed, M.M. Mahbubul; Hansen, Klaus Marius; Hammouda, Imed; Manikas, Konstantinos (Proceedings of The International Symposium on Open Collaboration, 2014)
Existing studies show that open source projects may enjoy high levels of socio-technical congruence despite their open and distributed character. Such observations are yet to be confirmed in the case of larger open source ecosystems in which developers contribute to different projects within the ecosystem. In this paper, we empirically study the relationships between the developer coordination activities and the project dependency structure in the Ruby ecosystem. Our motivation is to verify whether the ecosystem context maintains the high socio-technical congruence levels observed in many smaller scale FLOSS (Free/Libre Open Source Software) projects. Our study results show that the collaboration pattern among the developers in Ruby ecosystem is not necessarily shaped by the communication needs indicated by the dependencies among the ecosystem projects.

Software Developers Are Humans, Too! - Vasilescu, Bogdan (Proceedings of the Companion Publication of the 17th ACM Conference on Computer Supported Cooperative Work & Social Computing, 2014)
Open-source communities can be seen as knowledge-sharing ecosystems: participants learn from the community and from one another, and share their knowledge through contributions to the source code repositories or by offering support to users. With the emergence and growing popularity of social media sites targeting software developers (e.g., StackOverflow, GitHub), the paths through which knowledge flows within open-source software knowledge-sharing ecosystems are also beginning to change. My dissertation research seeks to raise our understanding of these changes.
Keywords: human aspects; open-source; software developers

Sourcerer: An infrastructure for large-scale collection and analysis of open-source code - Bajracharya, Sushil; Ossher, Joel; Lopes, Cristina (Science of Computer Programming, 2014)
A large amount of open source code is now available online, presenting a great potential resource for software developers. This has motivated software engineering researchers to develop tools and techniques to allow developers to reap the benefits of these billions of lines of source code. However, collecting and analyzing such a large quantity of source code presents a number of challenges. Although the current generation of open source code search engines provides access to the source code in an aggregated repository, they generally fail to take advantage of the rich structural information contained in the code they index. This makes them significantly less useful than Sourcerer for building state-of-the-art software engineering tools, as these tools often require access to both the structural and textual information available in source code.We have developed Sourcerer, an infrastructure for large-scale collection and analysis of open source code. By taking full advantage of the structural information extracted from source code in its repository, Sourcerer provides a foundation upon which state-of-the-art search engines and related tools can easily be built. We describe the Sourcerer infrastructure, present the applications that we have built on top of it, and discuss how existing tools could benefit from using Sourcerer.

Structural Changes Associated with the Temporal Dispersion of Teams: Evidence from Open Source Software Projects - Colazo, Jorge A. (47th International Hawai'i Conference on System Sciences (HICSS-47), 2014)
This study relies on Media Synchronicity Theory and Social Network Analysis to analyze how the structure of collaboration networks change when collaborating teams become temporally dispersed. The empirical test of hypotheses using ordinary least squares with archival data from 230 Open Source Software projects shows that the collaboration structure networks of more temporally dispersed teams are sparser and more centralized, and these associations are stronger in those teams exhibiting higher relative performance.

A Study of External Community Contribution to Open-source Projects on GitHub - Padhye, Rohan; Mani, Senthil; Sinha, Vibha Singhal (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
Open-source software projects are primarily driven by community contribution. However, commit access to such projects' software repositories is often strictly controlled. These projects prefer to solicit external participation in the form of patches or pull requests. In this paper, we analyze a set of 89 top-starred GitHub projects and their forks in order to explore the nature and distribution of such community contribution. We first classify commits (and developers) into three categories: core, external and mutant, and study the relative sizes of each of these classes through a ring-based visualization. We observe that projects written in mainstream scripting languages such as JavaScript and Python tend to include more external participation than projects written in upcoming languages such as Scala. We also visualize the geographic spread of these communities via geocoding. Finally, we classify the types of pull requests submitted based on their labels and observe that bug fixes are more likely to be merged into the main projects as compared to feature enhancements.
Keywords: community participation; core committers; external contribution; mining challenge; mining software repositories; msr challenge; Open-source software; pull requests

A Study of the Effect on Business Growth by Utilization and Contribution of Open Source Software in Japanese IT Companies - Noda, Tetsuo; Tansho, Terutaka (Open Source Software: Mobile Open Source Technologies, 2014)
To analyze how OSS effects business growth both through simple use and by deeper engagement as a stakeholder in OSS community, we did questionnaire research to Japanese IT companies in 2012 and 2013. We analyze the progress of utilization and contribution of OSS, and the impact on business growth indicators by them.

Studying software evolution using topic models - Stephen W. Thomas; Adams, Bram; Hassan, Ahmed E.; Blostein, Dorothea (Science of Computer Programming, 2014)
Topic models are generative probabilistic models which have been applied to information retrieval to automatically organize and provide structure to a text corpus. Topic models discover topics in the corpus, which represent real world concepts by frequently cooccurring words. Recently, researchers found topics to be effective tools for structuring various software artifacts, such as source code, requirements documents, and bug reports. This research also hypothesized that using topics to describe the evolution of software repositories could be useful for maintenance and understanding tasks. However, research has yet to determine whether these automatically discovered topic evolutions describe the evolution of source code in a way that is relevant or meaningful to project stakeholders, and thus it is not clear whether topic models are a suitable tool for this task. In this paper, we take a first step towards evaluating topic models in the analysis of software evolution by performing a detailed manual analysis on the source code histories of two well-known and well-documented systems, JHotDraw and jEdit. We define and compute various metrics on the discovered topic evolutions and manually investigate how and why the metrics evolve over time. We find that the large majority (87%–89%) of topic evolutions correspond well with actual code change activities by developers. We are thus encouraged to use topic models as tools for studying the evolution of a software system.
Keywords: Latent Dirichlet allocation; mining software repositories; software evolution; topic model

A Successful OSS Adaptation and Integration in an e-Learning Platform: TEC Digital - Chacon-Rivas, Mario; Garita, Cesar (Open Source Software: Mobile Open Source Technologies, 2014)
E-learning projects in many universities are focused on adapting or installing a software platform to upload teaching materials and sometimes to open discussion forums. However, it is totally possible to extend the learning management system (LMS) as a complete service platform for students and instructors including more advanced services. This paper shows the progressive integration of services and applications in TEC Digital as the open source e-learning platform of the Costa Rica Institute of Technology. This integration experience could be used as a case of study for other universities.

Theorizing Modes of Open Source Software Development - Aron Lindberg; Xuan Xiao; Kalle Lyytinen (47th International Hawai'i Conference on System Sciences (HICSS-47), 2014)
Open Source Software (OSS) development is distributed across actors and artifacts and involves translating diffuse representations into distinct sets of contiguous code artifacts. Despite the highly distributed and dynamic nature of OSS development, it is often described in unitary, monolithic terms – an unfortunate situation which masks considerable variance across OSS development processes. Therefore we explore reasons for systematic variance in these processes so as to enable more effective OSS development practices. Drawing on theory of distributed cognition, we develop a language of cognitive translations, which occur within and across distributed social arrangements and structural conditions of sharing knowledge. This language provides micro-foundations for understanding how different modes of OSS development emerge. Through examining how generative characteristics of social and structural distributions in OSS shape distinct development pathways, we propose a theoretically derived typology explaining the characteristics, dynamics, and conditions for success of different modes of OSS development.

Towards Understanding of Structural Attributes of Web APIs Using Metrics Based on API Call Responses - Janes, Andrea; Remencius, Tadas; Sillitti, Alberto; Succi, Giancarlo (Open Source Software: Mobile Open Source Technologies, 2014)
The latest trend across different industries is to move towards (open) web APIs. Creating a successful API, however, is not easy. A lot depends on consumers and their interest and willingness to work with the exposed interface. Structural quality, learning difficulty, design consistency, and backwards compatibility are some of the important factors in this process. The question, however, is how one can measure and track such attributes. This paper presents the beginnings of a measurement framework for web APIs that is based on the information readily available both to API providers and API consumers - API call responses. In particular, we analyze the tree-based hierarchical structure of JSON and XML data returned from API calls. We propose a set of easy-to-compute metrics as a starting point and describe sample usage scenarios. These metrics are illustrated by examples from some of the popular open web APIs.

Understanding contributor behaviour within Free/Libre/Open Source Software communities: A socialization perspective - Carillo, Kevin Daniel Andre (2014)
Attracting a large number of new contributors has been seen as a way to ensure the survival, long-term success, and sustainability of Free/Libre/Open Source Software (FLOSS) communities. However, this appears to be a necessary, but not a sufficient condition, as the well-being of FLOSS communities also relies on members performing behaviours that nurture and protect the community. Despite a large body of research on FLOSS communities, few studies have been undertaken to explore the influence of a participant’s socialization experience on their contribution behaviour. In addition, there has been relatively little research that has adopted a community-level view of FLOSS community participants’ contribution that goes beyond the mere notion of writing lines of code. The purpose of this study is to develop and rigorously test a socialization model that predicts contributor behaviour in the FLOSS community context. Drawing upon theories of socialization and citizenship behaviours from organizational behaviour research, this research develops and tests two separate but related research models. The first model proposes the direct impact of socialization factors on two performance-related dependent variables: task performance and community citizenship behaviours. The second model hypothesizes a mediating effect of two proximal socialization variables, social identification and social integration, between the socialization factors and the dependent variables. An exploratory study involving eleven FLOSS community leaders, managers, and experienced members was first conducted, to investigate the key variables that characterize FLOSS community newcomer socialization experience as well as the various instances of citizenship behaviours that are specific to the FLOSS community context. The analysis of the interview data revealed the existence of six socialization variables: task segregation, task purposefulness, interaction intensity, mentoring, joining structuredness, and supportiveness. Two sets of FLOSS community citizenship behaviours (CCB) were identified drawing on the citizenship behaviour literature. The first set, labelled CCB-I, comprised citizenship behaviours directed towards the benefit of individuals. The second set, CCB-P, included citizenship behaviours directed towards the benefit of the project. The findings were integrated in the two conceptual models. Subsequently, a research instrument was developed, following an extensive purification process that consisted of card sorting and expert review rounds, and a survey pretest. A pilot study assessed responses from 46 FLOSS contributors from two large FLOSS communities. Overall, the scales demonstrated high reliability and showed adequate construct validity. The analysis of the pilot study suggested the existence of a third CCB dimension, named CCB-C, that characterizes citizenship behaviours that are oriented towards the benefit of a project’s community. The main study was based on an online survey involving 327 respondents from twelve large FLOSS communities. Using Partial Least Squares (PLS), the collected data was used to test the two models. The results showed the overall superior predictive capability of the model hypothesizing the mediating effect of both social identification and social integration. Task performance was found to be directly predicted by task purposefulness as well as by interaction intensity and supportiveness through the mediation of social identification. Meanwhile, CCB was found to be impacted by the direct effect of task segregation and task purposefulness, and by interaction intensity and supportiveness through the mediation of both social identification and social integration. The existence of the third CCB dimension, CCB-C, was confirmed.

Understanding Contributor to Developer Turnover Patterns in OSS Projects: A Case Study of Apache Projects - Iqbal, Aftab (ISRN Software Engineering, 2014)
OSS projects are dynamic in nature. Developers contribute to a project for a certain period of time and later leave the project or join other projects of high interest. Hence, the OSS community always welcomes members who can attain the role of a developer in a project. In this paper, we investigate contributions made by members who have attained the role of a developer. In particular, we study the contributions made by the members in terms of bugs reported, comments on bugs, source-code patch submissions, and their social relation with other members of an OSS community. Further, we study the significance of nondevelopers contribution and investigate if and to what extent they play a role in the long-term survival of an OSS project. Moreover, we investigate the ratio of contributions made by a member before and after attaining the role of a developer. We have outlined 4 research questions in this regard and further discuss our findings based on the research questions by taking into account data from software repositories of 4 different Apache projects.
Keywords: apache

Understanding Coopetition in the Open-Source Arena: The Cases of WebKit and OpenStack - Teixeira, Jose (Proceedings of The International Symposium on Open Collaboration, 2014)
In an era of software crisis, the move of firms towards distributed software development teams is being challenged by emerging collaboration issues. On this matter, the open-source phenomenon may shed some light, as successful cases on distributed collaboration in the open-source community have been recurrently reported. In our research we explore collaboration networks in the WebKit and OpenStack high-networked open-source projects, by mining their source-code version-control-systems data with Social Network Analysis (SNA). Our approach allows us to observe how key events in the industry affect open-source collaboration networks over time. With our findings, we highlight the explanatory power from network visualizations capturing the collaborative dynamics of high-networked software projects over time. Moreover, we argue that competing companies that sell similar products in the same market, can collaborate in the open-source community while publicly manifesting intense rivalry (e.g. Apple vs Samsung patent-wars). After integrating our findings with the current body of theoretical knowledge in management strategy, economics, strategic alliances and coopetition, we propose the novel notion of open-coopetition, where rival firms collaborate with competitors in the open-source community. We argue that classical coopetition management theories do not fully explain the competitive and collaborative issues that are simultaneously present and interconnected in the WebKit and OpenStack open-source communities. We propose the development of the novel open-coopetition theory for a better understanding on how rival-firms collaborate with competitors by open-source manners.
Keywords: COLLABORATION; Competition; Coopetition; Ecosystems; FLOSS; Open-Coopetition; open-source; OSS; Strategic Alliances

Understanding "Watchers" on GitHub - Sheoran, Jyoti; Blincoe, Kelly; Kalliamvakou, Eirini; Damian, Daniela; Ell, Jordan (Proceedings of the 11th Working Conference on Mining Software Repositories, 2014)
Users on GitHub can watch repositories to receive notifications about project activity. This introduces a new type of passive project membership. In this paper, we investigate the behavior of watchers and their contribution to the projects they watch. We find that a subset of project watchers begin contributing to the project and those contributors account for a significant percentage of contributors on the project. As contributors, watchers are more confident and contribute over a longer period of time in a more varied way than other contributors. This is likely attributable to the knowledge gained through project notifications.
Keywords: github; mining challenge; msr challenge; repositories; Software Teams; Watchers

USB Device Management in GNU/Linux Systems - Deroncelé, EdilbertoBlez; Fuentes, AllanPierra; Tejera Hernández, DayanaCaridad; Cáceres Navarro, Haniel; Fírvida Donestévez, AbelAlfonso; Febles Parker, MichelEvaristo (Open Source Software: Mobile Open Source Technologies, 2014)
Protecting the access to USB ports has the same priority for information security than firewalls and antivirus software. Nowadays there are some tools that allow us to monitor and regulate the access to USB devices, but all of them are distributed under proprietary licenses. This work presents an application that solves the mentioned problem: ?’How controlling the access to USB mass storage devices in GNU/Linux Operating Systems?

Use of Open Software Tools for Data Offloading Techniques Analysis on Mobile Networks - Koo, JoséM.; Espino, JuanP.; Armuelles, Iván; Villarreal, Rubén (Open Source Software: Mobile Open Source Technologies, 2014)
This research aims to highlight the benefits of using free software based tools for studying a LTE mobile network with realistic parameters. We will overload this LTE network and offload it through data offloading techniques such as small cells and WiFi offload. For this research, discreteevent open software network simulator ns3 will be implemented. Ns3 is a network simulator based on the programming language C++, and has all the necessary libraries to simulate an LTE and WiFi network.
Keywords: Data Offloading; LTE; ns3; OSS for research and education; small cells; WiFi

Volunteer Attraction and Retention in Open Source Communities - Barcomb, Ann (Proceedings of The International Symposium on Open Collaboration, 2014)
The importance of volunteers in open source has led to the position of community manager becoming more common in foundations and projects. Yet the advice for volunteer management and retention is fragmented, incomplete, contradictory, and has not been empirically examined. Our aim is to fill this gap by creating a comprehensive guidebook of best practices drawing from open source practitioner guides and general literature on volunteering, and to subject a subset of practices to empirical study. A method for evaluating volunteer attrition in terms of value to the organization will also be developed.
Keywords: Community Management; FLOSS; open source; Recruitment; Service Duration; Volunteer Management; Volunteer Retention; Volunteers

When Are OSS Developers More Likely to Introduce Vulnerable Code Changes? A Case Study - Bosu, Amiangshu; Carver, JeffreyC.; Hafiz, Munawar; Hilley, Patrick; Janni, Derek (Open Source Software: Mobile Open Source Technologies, 2014)
We analyzed peer code review data of the Android Open Source Project (AOSP) to understand whether code changes that introduce security vulnerabilities, referred to as vulnerable code changes (VCC), occur at certain intervals. Using a systematic manual analysis process, we identified 60 VCCs. Our results suggest that AOSP developers were more likely to write VCCs prior to AOSP releases, while during the post-release period they wrote fewer VCCs.
Keywords: FOSS; open source; OSS; security; vulnerability

Who Contributes to What? Exploring Hidden Relationships between FLOSS Projects - Syeed, M.M.Mahbubul; Hammouda, Imed (Open Source Software: Mobile Open Source Technologies, 2014)
In this paper we address the challenge of tracking resembling open source projects by exploiting the information of which developers contribute to which projects. To do this, we have performed a social network study to analyze data collected from the Ohloh repository. Our findings suggest that the more shared contributors two projects have, the more likely they resemble with respect to properties such as project application domain, programming language used and project size.

An Adaptive Filter-Framework for the Quality Improvement of Open-Source Software Analysis. - Hannemann, Anna; Hackstein, Michael; Klamma, Ralf; Jarke, Matthias (Software Engineering, 2013)
Knowledge mining in Open-Source Software (OSS) brings a great benefit for software engineering (SE). The researchers discover, investigate, and even simulate the organization of development processes within open-source communities in order to understand the community-oriented organization and to transform its advantages into conventional SE projects. Despite a great number of different studies on OSS data, not much attention has been paid to the data filtering step so far. The noise within uncleaned data can lead to inaccurate conclusions for SE. A special challenge for data cleaning presents the variety of communicational and development infrastructures used by OSS projects. This paper presents an adaptive filter-framework supporting data cleaning and other preprocessing steps. The framework allows to combine filters in arbitrary order, defining which preprocessing steps should be performed. The filter-portfolio can by extended easily. A schema matching in case of cross-project analysis is available. Three filters - spam detection, quotation elimination and core periphery distinction - were implemented within the filter-framework. In the analysis of three large-scale OSS projects (BioJava, Biopython, BioPerl), the filtering led to a significant data modification and reduction. The results of text mining (sentiment analysis) and social network analysis on uncleaned and cleaned data differ significantly, confirming the importance of the data preprocessing step within OSS empirical studies.

All complaints are not created equal: text analysis of open source software defect reports - Raja, Uzma (Empirical Software Engineering, 2013)
As the use of Open Source Software (OSS) systems increases in the corporate environment, it is important to examine the maintenance process of these projects. OSS projects allow end users to directly submit reports in case of any operational issues. Timely resolution of these defect reports requires effective management of maintenance resources. This study analyzes the usefulness of the textual content of the defect reports as an early indicator of their resolution time. Text Mining techniques are used to categorize defect reports of five OSS projects. Significant variation in the defect resolution time amongst the resulting categories, for each of the sample projects, indicates that a text based classification of defect reports can be useful in early assessment of resolution time before source code level analysis. Such technique can assist in allocation of sufficient maintenance resources to targeted defects and also enable project teams to manage customer expectations regarding defect resolution times.

Analyzing Social Behavior of Software Developers Across Different Communication Channels - Iqbal, Aftab; M Karnstedt; M Hausenblas (25th International Conference on Software Engineering and Knowledge Engineering (SEKE), 2013)
Software developers use different project repositories (i.e., mailing list, bug tracking repositories, discussion forums etc.) to interact with each other or to solve software related problems. The growing interest in the usage of social media channels (i.e., Twitter, Facebook, LinkedIn) have also attracted the open source software community and software developers to adopt an identity in order to disseminate project-related information to a wider audience. Much research has been carried out to analyze the social behavior of software developers in different project repositories but so far no one has tried to study the social communication patterns of developers in other social media channels. We in this paper presents a new dimension to the social aspects of software developers and study if the social communication patterns of software developers is different on project repositories and social media channels (i.e., Twitter).
Keywords: communication; developer; social media

Apache Commits: Social Network Dataset - MacLean, Alexander C.; Knutson, Charles D. (10th Working Conference on Mining Software Repositories, 2013)
Building non-trivial software is a social endeavor. Therefore, understanding the social network of developers is key to the study of software development organizations. We present a graph representation of the commit behavior of developers within the Apache Software Foundation for 2010 and 2011. Relationships between developers in the network represent collaborative commit behavior. Several similarity and summary metrics have been pre-calculated. The data, along with the tools that were used to create it and some further discussion, can be found at: http://sequoia.cs.byu.edu/lab/?page=artifacts/apacheGraphs

Apache-Affiliated Twitter Screen Names: A Dataset - Squire, Megan (10th Working Conference on Mining Software Repositories (MSR2013), 2013)
This paper describes a new dataset containing Twitter screen names for members of the projects affiliated with the Apache Software Foundation (ASF). The dataset includes the confirmed Twitter screen names, as well as the real name as listed on Twitter, and the user identification as used within the Apache organization. The paper also describes the process used to collect and clean this data, and shows some sample queries for learning how to use the data. The dataset has been donated to the FLOSSmole project and is available for download (https://code. google.com/p/flossmole/downloads/detail?name=apacheTwitter2013-Jan.zip) or direct querying via a database client.
Keywords: apache; dataset; twitter

An application of data envelopment analysis to software quality assessment - Paschalidou, Georgia; Stiakakis, Emmanouil; Chatzigeorgiou, Alexander (Proceedings of the 6th Balkan Conference in Informatics, 2013)
Data Envelopment Analysis (DEA) is a non-parametric technique which involves the use of linear programming methods to measure the efficiency of a homogenous set of units. These units are known as Decision Making Units (DMUs) and defined by multiple input and output data. Efficiencies are measured relative to a piece-wise surface (efficient frontier) which envelops the data, thus justifying the name of the technique. Although DEA has been mostly used in production economics, its application in the context of software quality evaluation seems to be a promising approach. This study provides an application of DEA to assess the evolution of two open-source software projects in terms of selected metric values for successive versions of each project. What is really interesting in DEA is that a single efficiency score is calculated for each version despite the often convoluted overall picture of the metric values. According to a simplified view of DEA, there are two categories of units, the efficient (onto the efficient frontier) and the inefficient ones. Each inefficient unit is characterized by a reference set of peers which involves all the efficient units "operating" closer to that unit. Through the consideration of the reference set of the inefficient versions of each project, the metrics that require improvement, as well as the extent of improvement, could be estimated. These results could assist software developers in identifying design issues that require further improvement. Notwithstanding the fact that there are a number of issues to be further investigated, the applicability of DEA and other operations research tools in the context of software quality might yield interesting results.
Keywords: dea; design metrics; software evolution; software quality

Applying a Rule-Based Natural Language Classifier to Open Source Requirements: a Demonstration of Theory Exploration - Vlas, Radu; Robinson, William N. (2013 46th Hawaii International Conference on System Sciences (HICSS)2013 46th Hawaii International Conference on System Sciences, 2013)
Open source projects requirements are mostly informal, text descriptions found in requests, forums, and other correspondence. Understanding of such requirements can provide insight into the nature of open source projects. Previously, we have demonstrated the Requirements Classifier for Natural Language (RCNL), which aids in NL requirements analysis. Herein, we demonstrate how the RCNL can aid in theory building. From its application to 16 open source projects, we conjecture a simple wave theory of requirements innovation: innovations expressed in requirements appear as a wave that is reflected in a subsequent wave of features that is reflected in a subsequent wave of product downloads. Although the theory is a conjecture, the process of its exploration demonstrates how RCNL can be used to explore theories about open source projects -- theory exploration that would otherwise be intractable because of the difficulty in analyzing NL artifacts for requirements properties.

Authoritative Linked Data Descriptions of Debian Source Packages Using ADMS.SW - Olivier Berger; Christian Bac (IFIP Advances in Information and Communication TechnologyOpen Source Software: Quality Verification, 2013)
he Debian Package Tracking System is a Web dashboard for Debian contributors and advanced users. This central tool publishes the status of subsequent releases of source packages in the Debian distribution. It has been improved to generate RDF meta-data documenting the source packages, their releases and links to other packaging artifacts, using the ADMS.SW 1.0 model. This constitutes an authoritative source of machine-readable Debian “facts” and proposes a reference URI naming scheme for Linked Data resources about Debian packages. This should enable the interlinking of these Debian package descriptions with other ADMS.SW or DOAP descriptions of FLOSS projects available on the Semantic Web also using Linked Data principles. This will be particularly interesting for traceability with upstream projects whose releases are packaged in Debian, derivative distributions reusing Debian source packages, or with other FLOSS distributions.
Keywords: debian

The Babel of Software Development: Linguistic Diversity in Open Source - Vasilescu, Bogdan; Serebrenik, Alexander; Brand, MarkG.J. (Social Informatics, 2013)

Boa: A Language and Infrastructure for Analyzing Ultra-Large-Scale Software Repositories - Dyer, Robert; Nguyen, Hoan Anh; Rajan, Hridesh; Nguyen, Tien N. (35th Int'l Conference on Software Engineering (ICSE 2013), 2013)
In today’s software-centric world, ultra-large-scale software repositories, e.g. SourceForge (350,000+ projects), GitHub (250,000+ projects), and Google Code (250,000+ projects) are the new library of Alexandria. They contain an enormous corpus of software and information about software. Scientists and engineers alike are interested in analyzing this wealth of information both for curiosity as well as for testing important hypotheses. However, systematic extraction of relevant data from these repositories and analysis of such data for testing hypotheses is hard, and best left for mining software repository (MSR) experts! The goal of Boa, a domain-specific language and infrastructure described here, is to ease testing MSR-related hypotheses. We have implemented Boa and provide a web-based interface to Boa’s infrastructure. Our evaluation demonstrates that Boa substantially reduces programming efforts, thus lowering the barrier to entry. We also see drastic improvements in scalability. Last but not least, reproducing an experiment conducted using Boa is just a matter of re-running small Boa programs provided by previous researchers.
Keywords: ease of use; forge; github; google code; lower barrier to entry; mining; repository; reproducible; scalable; Software; sourceforge

Bug Resolution Catalysts: Identifying Essential Non-committers from Bug Repositories - Mani, Senthil; Seema Nagar; Debdoot Mukherjee; Ramasuri Narayanam; Sinha, Vibha Singhal; Amit A. Nanavati (10th Working Conference on Mining Software Repositories, 2013)
Bugs are inevitable in software projects. Resolving bugs is the primary activity in software maintenance. Developers, who fix bugs through code changes, are naturally important participants in bug resolution. However, there are other participants in these projects who do not perform any code commits. They can be reporters reporting bugs; people having a deep technical know-how of the software and providing valuable insights on how to solve the bug; bug-tossers who re-assign the bugs to the right set of developers. Even though all of them act on the bugs by tossing and commenting, not all of them may be crucial for bug resolution. In this paper, we formally define essential non-committers and try to identify these bug resolution catalysts. We empirically study 98304 bug reports across 11 open source and 5 commercial software projects for validating the existence of such catalysts. We propose a network analysis based approach to construct a Minimal Essential Graph that identifies such people in a project. Finally, we suggest ways of leveraging this information for bug triaging and bug report summarization.

Building and mining a repository of design pattern instances: Practical and research benefits - Apostolos Ampatzoglou; Olia Michou; Ioannis Stamelos (Entertainment Computing, 2013)
Design patterns are well-known design solutions that are reported to produce substantial benefits with respect to software quality. However, to our knowledge there are no scientific efforts on gathering information on software projects that use design patterns. This paper introduces a web repository of design patterns instances that have been used in open source projects. The usefulness of such a repository lies in the provision of a base of knowledge, where developers can identify reusable components and researchers can find a mined data set. Currently, 141 open source projects have been considered and more than 4500 pattern instances have been found and recorded in the database of the repository. The evaluation of the repository has been performed from an academic and a practical point of view. The results suggest that the repository can be useful for both experienced and inexperienced users. However, the benefits of using the repository are more significant for inexperienced users.
Keywords: flossmole cited; repository

Communication in Open Source Software Development Mailing Lists - Guzzi, Anja; Bacchelli, Alberto; Lanza, Michele; Pinzger, Martin; van Deursen, Arie (10th Working Conference on Mining Software Repositories, 2013)
Open source software (OSS) development teams use electronic means, such as emails, instant messaging, or forums, to conduct open and public discussions. Researchers investigated mailing lists considering them as a hub for project communication. Prior work focused on specific aspects of emails, for example the handling of patches, traceability concerns, or social networks. This led to insights pertaining to the investigated aspects, but not to a comprehensive view of what developers communicate about. Our objective is to increase the understanding of development mailing lists communication. We quantitatively and qualitatively analyzed a sample of 506 email threads from the development mailing list of a major OSS project, Lucene. Our investigation reveals that implementation details are discussed only in about 35% of the threads, and that a range of other topics is discussed. Moreover, core developers participate in less than 75% of the threads. We observed that the development mailing list is not the main player in OSS project communication, as it also includes other channels such as the issue repository.
Keywords: email; lucene; mailling list

Community Dynamics in Open Source Software Projects: Aging and Social Reshaping - Hannemann, Anna; Klamma, Ralf (IFIP Advances in Information and Communication TechnologyOpen Source Software: Quality Verification, 2013)
An undeniable factor for an open source software (OSS) project success is a vital community built around it. An OSS community not only needs to be established, but also to be persisted. This is not guaranteed considering the voluntary nature of participation in OSS. The dynamic analysis of the OSS community evolution can be used to extract indicators to rate the current stability of a community and to predict its future development. Despite the great amount of studies on mining project communication and development repositories, the evolution of OSS communities is rarely addressed. This paper presents an approach to analyze the OSS community history. We combine adapted demography measures to study community aging and social analysis to investigate the dynamics of community structures. The approach is applied to the communication and development history of three bioinformatics OSS communities over eleven years. First, in all three projects a survival rate pattern is identified. This finding allows us to define the minimal number of newcomers required for the further positive community growth. Second, dynamic social analysis shows that the node betweenness in combination with the network diameter can be used as an indicator for significant changes in the community core and the quality of community recovery after these modifications.

A Dataset from Change History to Support Evaluation of Software Maintenance Tasks - Bogdan Dit; Andrew Holtzhauer; Poshyvanyk, Denys; Kagdi, Huzefa (10th Working Conference on Mining Software Repositories, 2013)
Approaches that support software maintenance need to be evaluated and compared against existing ones, in order to demonstrate their usefulness in practice. However, oftentimes the lack of well-established sets of benchmarks leads to situations where these approaches are evaluated using different datasets, which results in biased comparisons. In this data paper we describe and make publicly available a set of benchmarks from six Java applications, which can be used in the evaluation of various software engineering (SE) tasks, such as feature location and impact analysis. These datasets consist of textual description of change requests, the locations in the source code where they were implemented, and execution traces. Four of the benchmarks were already used in several SE research papers, and two of them are new. In addition, we describe in detail the methodology used for generating these benchmarks and provide a suite of tools in order to encourage other researchers to validate our datasets and generate new benchmarks for other subject software systems. Our online appendix: http://www.cs.wm.edu/semeru/data/msr13/

Discovering, Reporting, and Fixing Performance Bugs - Adrian Nistor; Tian Jiang; Tan, Lin (10th Working Conference on Mining Software Repositories, 2013)
Software performance is critical for how users perceive the quality of software products. Performance bugs---programming errors that cause significant performance degradation---lead to poor user experience and low system throughput. Designing effective techniques to address performance bugs requires a deep understanding of how performance bugs are discovered, reported, and fixed. In this paper, we study how performance bugs are discovered, reported to developers, and fixed by developers, and compare the results with those for non-performance bugs. We study performance and non-performance bugs from three popular code bases: Eclipse JDT, Eclipse SWT, and Mozilla. First, we find little evidence that fixing performance bugs has a higher chance to introduce new functional bugs than fixing non-performance bugs, which implies that developers may not need to be overconcerned about fixing performance bugs. Second, although fixing performance bugs is about as error-prone as fixing nonperformance bugs, fixing performance bugs is more difficult than fixing non-performance bugs, indicating that developers need better tool support for fixing performance bugs and testing performance bug patches. Third, unlike many non-performance bugs, a large percentage of performance bugs are discovered through code reasoning, not through users observing the negative effects of the bugs (e.g., performance degradation) or through profiling. The result suggests that techniques to help developers reason about performance, better test oracles, and better profiling techniques are needed for discovering performance bugs.
Keywords: bugs; eclipse; mozilla; performance bugs

Discovery of Technical Expertise from Open Source Code Repositories - Venkataramani, Rahul; Gupta, Atul; Asadullah, Allahbaksh; Muddu, Basavaraju; Bhat, Vasudev (Proceedings of the 22Nd International Conference on World Wide Web Companion, 2013)
Online Question and Answer websites for developers have emerged as the main forums for interaction during the software development process. The veracity of an answer in such websites is typically verified by the number of 'upvotes' that the answer garners from peer programmers using the same forum. Although this mechanism has proved to be extremely successful in rating the usefulness of the answers, it does not lend itself very elegantly to model the expertise of a user in a particular domain. In this paper, we propose a model to rank the expertise of the developers in a target domain by mining their activity in different opensource projects. To demonstrate the validity of the model, we built a recommendation system for StackOverflow which uses the data mined from GitHub.
Keywords: github; knowledge discovery; recommendations; source code repository; stackoverflow; technical expertise

Do Software Categories Impact Coupling Metrics? - Lucas Batista Leite de Souza; Marcelo de Almeida Maia (10th Working Conference on Mining Software Repositories, 2013)
Software metrics is a valuable mechanism to assess the quality of software systems. Metrics can help the automated analysis of the growing data available in software repositories. Coupling metrics is a kind of software metrics that have been extensively used since the seventies to evaluate several software properties related to maintenance, evolution and reuse tasks. For example, several works have shown that we can use coupling metrics to assess the reusability of software artifacts available in repositories. However, thresholds for software metrics to indicate adequate coupling levels are still a matter of discussion. In this paper, we investigate the impact of software categories on the coupling level of software systems. We have found that different categories may have different levels of coupling, suggesting that we need special attention when comparing software systems in different categories and when using predefined thresholds already available in the literature.

A Dual Model of Open Source License Growth - Hofmann, Gottfried; Dirk Riehle; Carsten Kolassa; Mauerer, Wolfgang (IFIP Advances in Information and Communication TechnologyOpen Source Software: Quality Verification, 2013)
Every open source project needs to decide on an open source license. This decision is of high economic relevance: Just which license is the best one to help the project grow and attract a community? The most common question is: Should the project choose a restrictive (reciprocal) license or a more permissive one? As an important step towards answering this question, this paper analyses actual license choice and correlated project growth from ten years of open source projects. It provides closed analytical models and finds that around 2001 a reversal in license choice occurred from restrictive towards permissive licenses.
Keywords: ohloh

The Eclipse and Mozilla Defect Tracking Dataset: A Genuine Dataset for Mining Bug Information - Lamkanfi, Ahmed; Javier Pérez; Demeyer, Serge (10th Working Conference on Mining Software Repositories, 2013)
The analysis of bug reports is an important subfield within the mining software repositories community. It explores the rich data available in defect tracking systems to uncover interesting and actionable information about the bug triaging process. While bug data is readily accessible from systems like Bugzilla and JIRA, a common database schema and a curated dataset could significantly enhance future research because it allows for easier replication. Consequently, in this paper we propose the Eclipse and Mozilla Defect Tracking Dataset, a representative database of bug data, filtered to contain only genuine defects (i.e., no feature requests) and designed to cover the whole bug-triage life cycle (i.e., store all intermediate actions). We have used this dataset ourselves for predicting bug severity, for studying bug-fixing time and for identifying erroneously assigned components. github.com/ansymo/msr2013-bug_dataset

Effect on Business Growth by Utilization and Contribution of Open Source Software in Japanese IT Companies - Noda, Tetsuo; Tansho, Terutaka; Coughlan, Shane (Springer Berlin Heidelberg, 2013)
The expanded use of Open Source Software (OSS), and the expansion of the market caused by this adoption has led to a corresponding increase in the number of businesses acting as stakeholders in the field. Some of these are pure users of OSS technology but a great number are developers of such technology, and can be understood to have a substantial investment in this paradigm. It is reasonable to assume that such businesses are rational actors, and that their investment or contribution to the field implies a positive economic benefit either currently obtained or assumed as a return in the future. This paper analyzes how OSS affects Japanese IT companies’ business growth both through simple use and by deeper engagement as a stakeholder in OSS community. This is the first time that such a link between the utilization of OSS and economic growth has been explored in the context of Japan, and it can hopefully lay a foundation for further study regarding the real economic value of this approach to software.

The Effects of Diversity in Global, Distributed Collectives: A Study of Open Source Project Success - Sherae Daniel; Ritu Agarwal; Stewart, Katherine J. (Information Systems Research, 2013)
Diversity is a defining characteristic of global collectives facilitated by the Internet. Though substantial evidence suggests that diversity has profound implications for a variety of outcomes including performance, member engagement, and withdrawal behavior, the effects of diversity have been predominantly investigated in the context of organizational workgroups or virtual teams. We use a diversity lens to study the success of nontraditional virtual work groups exemplified by open source software (OSS) projects. Building on the diversity literature, we propose that three types of diversity (separation, variety, and disparity) influence two critical outcomes for OSS projects: community engagement and market success. We draw on the OSS literature to further suggest that the effects of diversity on market success are moderated by the application development stage. We instantiate the operational definitions of three forms of diversity to the unique context of open source projects. Using archival data from 357 projects hosted on SourceForge, we find that disparity diversity, reflecting variation in participants' contribution-based reputation, is positively associated with success. The impact of separation diversity, conceptualized as culture and measured as diversity in the spoken language and country of participants, has a negative impact on community engagement but an unexpected positive effect on market success. Variety diversity, reflected in dispersion in project participant roles, positively influences community engagement and market success. The impact of diversity on market success is conditional on the development stage of the project. We discuss how the study's findings advance the literature on antecedents of OSS success, expand our theoretical understanding of diversity, and present the practical implications of the results for managers of distributed collectives.

The Emergence of Quality Assurance Practices in Free/Libre Open Source Software: A Case Study - Barham, Adina (IFIP Advances in Information and Communication TechnologyOpen Source Software: Quality Verification, 2013)
As the user base of Free/Libre Open Source Software (FLOSS) diversifies, the need for higher quality is becoming more evident. This implies a more complex development model that includes various steps which were previously associated exclusively with proprietary development such as a formal quality assurance step (QA). However, little research has been done on how implementing formal quality assurance impacts the structure of FLOSS communities. This study aims to start filling this gap by analyzing interactions within such a community. Plone is just one among many FLOSS projects that acknowledged the importance of verification by implementing a quality assurance step.

An Empirical Study of the Fault-Proneness of Clone Mutation and Clone Migration - Shuai Xie; Foutse Khomh; Ying Zou (10th Working Conference on Mining Software Repositories, 2013)
When implementing new features into a software system, developers may duplicate several lines of code to reuse some existing code segments. This action creates code clones in the software system. The literature has documented different types of code clone (e.g., Type-1, Type-2, and Type-3). Once created, code clones evolve as they are modified during both the development and maintenance phases of the software system. The evolution of code clones across the revisions of a software system is known as a clone genealogy. Existing work has investigated the fault-proneness of Type-1 and Type-2 clone genealogies. In this study, we investigate clone genealogies containing Type-3 clones. We analyze three long lived software systems APACHE-ANT, ARGOUML, and JBOSS, which are all written in JAVA. Using the NICAD clone detection tool, we build clone genealogies and examine two evolutionary phenomena on clones: the mutation of the type of a clone during the evolution of a system, and the migration of clone segments across the repositories of a software system. Results show that 1) mutation and migration occur frequently in software systems; 2) the mutation of a clone group to Type-2 or Type-3 clones increases the risk for faults; 3) increasing the distance between code segments in a clone group also increases the risk for faults. Index Terms: Types of clones; clone genealogy; clone migration; fault-proneness.

Evolution of Open Source Software Projects: A Systematic Literature Review - Syeed, Mahbubul; Hammouda, Imed; Syatä, Tarja (Journal of Software, 2013)
Open Source Software (OSS) is continuously gaining acceptance in commercial organizations. It is in this regard that those organizations strive for a better understanding of evolutionary aspects of OSS projects. The study of evolutionary patterns of OSS projects and communities has received substantial attention from the research community over the last decade. These efforts have resulted in an ample set of research results for which there is a need for up-to-date comprehensive overviews and literature surveys. This paper reports on a systematic literature survey aimed at the identification and structuring of research on evolution of OSS projects. In this review we systematically selected and reviewed 101 articles published in relevant venues. The study outcome provides insight in what constitutes the main contributions of the field, identifies gaps and opportunities, and distills several important future research directions.
Keywords: flosshub

The evolution of the laws of software evolution - Herraiz, Israel; Rodriguez, Daniel; Gregorio Robles; Jesus M. Gonzalez-Barahona (ACM Computing Surveys, 2013)
After more than 40 years of life, software evolution should be considered as a mature field. However, despite such a long history, many research questions still remain open, and controversial studies about the validity of the laws of software evolution are common. During the first part of these 40 years the laws themselves evolved to adapt to changes in both the research and the software industry environments. This process of adaption to new paradigms, standards, and practices stopped about 15 years ago, when the laws were revised for the last time. However, most controversial studies have been raised during this latter period. Based on a systematic and comprehensive literature review, in this paper we describe how and when the laws, and the software evolution field, evolved. We also address the current state of affairs about the validity of the laws, how they are perceived by the research community, and the developments and challenges that are likely to occur in the coming years.

Exploring Collaboration Networks in Open-Source Projects - Jermakovics, Andrejs; Sillitti, Alberto; Succi, Giancarlo (IFIP Advances in Information and Communication TechnologyOpen Source Software: Quality Verification, 2013)
Analysis of developer collaboration networks presents an opportunity for understanding and thus improving the software development process. Discovery of these networks, however, presents a challenge since the collaboration relationships are initially not known. In this work we apply an approach for discovering collaboration networks of open source developers from Version Control Systems (VCS). It computes similarities among developers based on common file changes, constructs the network of collaborating developers and applies filtering techniques to improve the readability of the visualized network. We use the approach in case studies of three different projects from open source (phpMyAdmin, Eclipse Data Tools Platform and Gnu Compiler Collection) to learn their organizational structure and patterns. Our results indicate that with little effort the approach is capable of revealing aspects of these projects that were previously not known or would require a lot of effort to discover manually via other means, such as reading project documentation and forums.

Finding Source Code on the Web for Remix and Reuse - Bajracharya, Sushil Krishna (Infrastructure for Building Code Search Applications for Developers, 2013)
The large availability of open source code on the Web provides great opportunities to build useful code search applications for developers. Building such applications requires addressing several challenges inherent in collecting and analyzing code from open source repositories to make them available for search. An infrastructure that supports collection, analysis, and search services for open source code available on the Web can greatly facilitate building effective code search applications. This chapter presents such an infrastructure called Sourcerer that facilitates collection, analysis, and search of source code available in code repositories on the Web. This chapter provides useful information to researchers and implementors of code search applications interested in harnessing the large availability of source code in the repositories on the Web. In particular, this chapter highlights key aspects of Sourcerer that supports combining Software Engineering and Information Retrieval techniques to build effective code search applications.
Keywords: code search; flossmole cited

Gendered Patterns of Politeness in Free/Libre Open Source Software Development - Moon, Eunyoung (2013 46th Hawaii International Conference on System Sciences (HICSS)2013 46th Hawaii International Conference on System Sciences, 2013)

The GHTorrent dataset and tool suite - Gousios, Georgios (MSR ’13: Proceedings of the 9th Working Conference on Mining Software Repositories, 2013)
A common requirement of many empirical software engineering studies is the acquisition and curation of data from software repositories. During the last few years, GitHub has emerged as a popular project hosting, mirroring and collaboration platform. GitHub provides an extensive REST API, which enables researchers to retrieve both the commits to the projects’ repositories and events generated through user actions on project resources. GHTorrent aims to create a scalable off line mirror of GitHub’s event streams and persistent data, and offer it to the research community as a service. In this paper, we present the project’s design and initial implementation and demonstrate how the provided datasets can be queried and processed.

A Historical Dataset for the Gnome Ecosystem - Mathieu Goeminne; Maëlick Claes; Mens, Tom (10th Working Conference on Mining Software Repositories, 2013)
We present a dataset of the open source software ecosystem Gnome from a social point of view. We have collected historical data about the contributors to all Gnome projects stored on git.gnome.org, taking into account the problem of identity matching, and associating different activity types to the contributors. This type of information is very useful to complement the traditional, source-code related information one can obtain by mining and analyzing the actual source code. The dataset can be obtained at https://bitbucket.org/mgoeminne/sgl-flossmetric-dbmerge.
Keywords: cvsanaly; flossmetrics; gnome

How does Context affect the Distribution of Software Maintainability Metrics? - Zhang, Feng; Audris Mockus; Ying Zou; Foutse Khomh; Hassan, Ahmed E. (Proceedings of the 29th IEEE International Conference on Software Maintainability, 2013)
Software metrics have many uses, e.g., defect prediction, effort estimation, and benchmarking an organization against peers and industry standards. In all these cases, metrics may depend on the context, such as the programming language. Here we aim to investigate if the distributions of commonly used metrics do, in fact, vary with six context factors: application domain, programming language, age, lifespan, the number of changes, and the number of downloads. For this preliminary study we select 320 nontrivial software systems from SourceForge. These software systems are randomly sampled from nine popular application domains of SourceForge. We calculate 39 metrics commonly used to assess software maintainability for each software system and use Kruskal Wallis test and Mann-Whitney U test to determine if there are significant differences among the distributions with respect to each of the six context factors. We use Cliff’s delta to measure the magnitude of the differences and find that all six context factors affect the distribution of 20 metrics and the programming language factor affects 35 metrics. We also briefly discuss how each context factor may affect the distribution of metric values.We expect our results to help software benchmarking and other software engineering methods that rely on these commonly used metrics to be tailored to a particular context.
Keywords: benchmark; context; contextual factor; flossmole; large scale; metrics; mining software repositories; sampling; software maintainability; sourceforge; static metrics

How Healthy Is My Project? Open Source Project Attributes as Indicators of Success - Piggot, James; Amrit, Chintan (IFIP Advances in Information and Communication Technology Open Source Software: Quality Verification, 2013)
Determining what factors can influence the successful outcome of a software project has been labeled by many scholars and software engineers as a difficult problem. In this paper we use machine learning to create a model that can determine the stage a software project has obtained with some accuracy. Our model uses 8 Open Source project metrics to determine the stage a project is in. We validate our model using two performance measures; the exact success rate of classifying an Open Source Software project and the success rate over an interval of one stage of its actual performance using different scales of our dependent variable. In all cases we obtain an accuracy of above 70% with one away classification (a classification which is away by one) and about 40% accuracy with an exact classification. We also determine the factors (according to one classifier) that uses only eight variables among all the variables available in SourceForge, that determine the health of an OSS project.
Keywords: flossmole; sourceforge

Identifying Success Factors for the Mozilla Project - Viseur, Robert (IFIP Advances in Information and Communication Technology Open Source Software: Quality Verification, 2013)
The publication of the Netscape source code under free software license and the launch of the Mozilla project constitute a pioneering initiative in the field of free and open source software. However, five years after the publication came years of decline. The market shares rose again after 2004 with the lighter Firefox browser. We propose a case study covering the period from 1998 to 2012. We identify the factors that explain the evolution of the Mozilla project. Our study deepens different success factors identified in the literature. It is based on authors’ experience as well as the abundant literature dedicated to the Netscape company and the Mozilla project. It particularly highlights the importance of the source code complexity, its modularity, the responsibility assignment and the existence of an organisational sponsorship.

IFIP Advances in Information and Communication Technology Open Source Software: Quality Verification Technological Innovation and Resource Bricolage in Firms: The Role of Open Source Software - Mahajan, Aarti; Clarysse, Bart (Springer Berlin Heidelberg, 2013)
Technological resources have been an important source of innovation in companies. They play a key role in the development of new products and services. However, the upfront investment in technical resources to enable the development of these new products and services can be quite high. Therefore, managers ask for well elaborated business cases before making investments. These business cases rely on market research to back up their assumptions rather than in-market testing. We argue that the advent of open source software (OSS) creates an opportunity space for companies to build low-cost prototypes and test their ideas in the market. Little is known about how OSS plays a role in allowing these firms to enhance product development. Using qualitative case studies, the paper sheds light on how OSS acts as a bricolage mechanism for technological innovation in the ICT services industry.

IFIP Advances in Information and Communication Technology Open Source Software: Quality Verification Empirical Study of the Relation between Open Source Software Use and Productivity of Japan’s Information Service Industries - Noda, Tetsuo; Tanihana, Keisuke (Springer Berlin Heidelberg, 2013)
This paper analyzes the relation between OSS (Open Source Software) use and the performance of Japanese information service industry. We first estimate the market value of OSS, an issue which only a few studies have specifically addressed. The results are then used to analyze the economic effect of OSS. Although our study has some methodological limitations regarding the calculation of the market value of OSS, we demonstrate that the economic effect of OSS is generally positive.

The Impact of Tangled Code Changes - Kim Herzig; Zeller, Andreas (10th Working Conference on Mining Software Repositories, 2013)
When interacting with version control systems, developers often commit unrelated or loosely related code changes in a single transaction. When analyzing the version history, such tangled changes will make all changes to all modules appear related, possibly compromising the resulting analyses through noise and bias. In an investigation of ﬁve open-source JAVA projects, we found up to 15% of all bug ﬁxes to consist of multiple tangled changes. Using a multi-predictor approach to untangle changes, we show that on average at least 16.6% of all source ﬁles are incorrectly associated with bug reports. We recommend better change organization to limit the impact of tangled changes.
Keywords: bias; data quality; history; java; mining software repositories; noise; tangled code changes; version control

Improving Bug Localization using Correlations in Crash Reports - Shaohua Wang; Foutse Khomh; Ying Zou (10th Working Conference on Mining Software Repositories, 2013)
Nowadays, many software organizations rely on automatic problem reporting tools to collect crash reports directly from users' environments. These crash reports are later grouped together into crash types. Usually, developers prioritize crash types based on the number of crash reports and file bugs for the top crash types. Because a bug can trigger a crash in different usage scenarios, different crash types are sometimes related to a same bug. Two bugs are correlated when the occurrence of one bug causes the other bug to occur. We refer to a group of crash types related to identical or correlated bugs, as a crash correlation group. In this paper, we propose three rules to identify correlated crash types automatically. We also propose an algorithm to locate and rank buggy files using crash correlation groups. Through an empirical study on Firefox and Eclipse, we show that the three rules can identify crash correlation groups with a precision of 100% and a recall of 90% for Firefox and a precision of 79% and a recall of 65% for Eclipse. On the top three buggy file candidates, the proposed bug localization algorithm achieves a recall of 62% and a precision of 42% for Firefox and a recall of 52% and a precision of 50% for Eclipse. On the top 10 buggy file candidates, the recall increases to 92% for Firefox and 90% for Eclipse. Developers can combine the proposed crash correlation rules with the new bug localization algorithm to identify and fix correlated crash types all together.
Keywords: eclipse; Firefox

Intensive Metrics for the Study of the Evolution of Open Source Projects: Case Studies from Apache Software Foundation Projects - Gala, Santiago; Gregorio Robles; Jesus M. Gonzalez-Barahona; Herraiz Tabernero, Israel (10th Working Conference on Mining Software Repositories, 2013)
Based on the empirical evidence that the ratio of email messages in public mailing lists to versioning system commits has remained relatively constant along the history of the Apache Software Foundation (ASF), this paper has as goal to study what can be inferred from such a metric for projects of the ASF. We have found that the metric seems to be an intensive metric as it is independent of the size of the project, its activity, or the number of developers, and remains relatively independent of the technology or functional area of the project. Our analysis provides evidence that the metric is related to the technical effervescence and popularity of project, and as such can be a good candidate to measure its healthy evolution. Other, similar metrics -like the ratio of developer messages to commits and the ratio of issue tracker messages to commits- are studied for several projects as well, in order to see if they have similar characteristics.

Interlinking Developer Identities within and across Open Source Projects: The Linked Data Approach - Iqbal, Aftab; Hausenblas, Michael (ISRN Software Engineering, 2013)
Software developers use various software repositories in order to interact with each other or to solve related problems. These repositories provide a rich source of information for a wide range of tasks. However, one issue to overcome in order to make this information useful is the identification and interlinking of multiple identities of developers. In this paper, we propose a Linked Data-based methodology to interlink and integrate multiple identities of a developer found in different software repositories of a project as well as across repositories of multiple projects. Providing such interlinking will enable us to keep track of a developer’s activity not only within a single project but also across multiple projects. The methodology will be presented in general and applied to 5 Apache projects as a case study. Further, we show that the few methods suggested so far are not always appropriate to overcome the developer identification problem.
Keywords: developer; identity; linked data

INVocD: Identifier Name Vocabulary Dataset - Simon Butler; Wermelinger, Michel; Yu, Yijun; Helen Sharp (10th Working Conference on Mining Software Repositories, 2013)
INVocD is a database of the identifier name declarations and vocabulary found in 60 FLOSS Java projects where the source code structure is recorded and the identifier name vocabulary is made directly available, offering advantages for identifier name research over conventional source code models. The database has been used to support a range of research projects from identifier name analysis to concept location, and provides many opportunities to researchers. INVocD may be downloaded from http://oro.open.ac.uk/36992

Is It All Lost? A Study of Inactive Open Source Projects - Khondu, Jymit; Capiluppi, Andrea; Stol, Klaas (IFIP Advances in Information and Communication Technology Open Source Software: Quality Verification, 2013)
Open Source Software (OSS) proponents suggest that when developers lose interest in their project, their last duty is to “hand it off to a competent successor.” However, the mechanisms of such a hand-off are not clear, or widely known among OSS developers. As a result, many OSS projects, after a certain long period of evolution, stop evolving, in fact becoming “inactive” or “abandoned” projects. This paper presents an analysis of the population of projects contained within one of the largest OSS repositories available (SourceForge.net), in order to describe how projects abandoned by their developers can be identified, and to discuss the attributes and characteristics of these inactive projects. In particular, the paper attempts to differentiate projects that experienced maintainability issues from those that are inactive for other reasons, in order to be able to correlate common characteristics to the “failure” of these projects.
Keywords: sourceforge

It’s Not a Bug, It’s a Feature: How Misclassification Impacts Bug Prediction - Kim Herzig; Sascha Just; Zeller, Andreas (35th Int'l Conference on Software Engineering (ICSE 2013), 2013)
In a manual examination of more than 7,000 issue reports from the bug databases of five open-source projects, we found 33.8% of all bug reports to be misclassified—that is, rather than referring to a code fix, they resulted in a new feature, an update to documentation, or an internal refactoring. This misclassification introduces bias in bug prediction models, confusing bugs and features: On average, 39% of files marked as defective actually never had a bug. We discuss the impact of this misclassification on earlier studies and recommend manual data validation for future studies.
Keywords: bias; bug reports; data quality; mining software repositories; noise

Linchpin Developers in Open Source Software Projects - Corona, Erika Ingrid Mastranzo; Rossi, Bruno (Artificial Intelligence and Applications, 2013)
In Open Source Software (OSS) development, the so-called linchpin developers are those that contribute contemporaneously to several projects, contributing to keeping the community tied together. While such developers have been identified in previous research, their importance within the OSS community has not been widely discussed. The main objective of this work is to analyze their “weaving” role across projects. With this aim, we mined software repositories, using text mining techniques as log-likehood ratio and co-word analysis, further building social networks of developers within emerging communities. The findings show that linchpin developers generally attach in a preferential way to projects in a single specific domain. They tend to be more “project managers”, and “all-hands-persons”, meaning that they bring multi-disciplinary experience across projects. They tend to cover the same role across projects. They generally have high centrality in their projects, and contribute to create projects that ease the transition from a fragmented projects community to a more core-periphery community.
Keywords: flossmole

Linux Variability Anomalies: What Causes Them and How Do They Get Fixed? - Sarah Nadi; Christian Dietrich; Reinhard Tartler; Holt, Richard C.; Daniel Lohmann (10th Working Conference on Mining Software Repositories, 2013)
The Linux kernel is one of the largest configurable open source software systems implementing static variability. In Linux, variability is scattered over three different artifacts: source code files, Kconfig files, and Makefiles. Previous work detected inconsistencies between these artifacts that led to anomalies in the intended variability of Linux. We call these variability anomalies. However, there has been no work done to analyze how these variability anomalies are introduced in the first place, and how they get fixed. In this work, we provide an analysis of the causes and fixes of variability anomalies in Linux. We first perform an exploratory case study that uses an existing set of patches which solve variability anomalies to identify patterns for their causes. The observations we make from this dataset allow us to develop four research questions which we then answer in a confirmatory case study on the scope of the whole Linux kernel. We show that variability anomalies exist for several releases in the kernel before they get fixed, and that contrary to our initial suspicion, typos in feature names do not commonly cause these anomalies. Our results show that variability anomalies are often introduced through incomplete patches that change Kconfig definitions without properly propagating these changes to the rest of the system. Anomalies are then commonly fixed through changes to the code rather than to Kconfig files.

Management of community contributions - Bettenburg, Nicolas; Hassan, Ahmed E.; Adams, Bram; Daniel M. German (Empirical Software Engineering, 2013)
In recent years, many companies have realized that collaboration with a thriving user or developer community is a major factor in creating innovative technology driven by market demand. As a result, businesses have sought ways to stimulate contributions from developers outside their corporate walls, and integrate external developers into their development process. To support software companies in this process, this paper presents an empirical study on the contribution management processes of two major, successful, open source software ecosystems. We contrast a for-profit (ANDROID) system having a hybrid contribution style, with a not-for-profit (LINUX kernel) system having an open contribution style. To guide our comparisons, we base our analysis on a conceptual model of contribution management that we derived from a total of seven major open-source software systems. A quantitative comparison based on data mined from the ANDROID code review system and the LINUX kernel code review mailing lists shows that both projects have significantly different contribution management styles, suited to their respective market goals, but with individual advantages and disadvantages that are important for practitioners. Contribution management is a real-world problem that has received very little attention from the research community so far. Both studied systems (LINUX and ANDROID) employ different strategies and techniques for managing contributions, and both approaches are valuable examples for practitioners. Each approach has specific advantages and disadvantages that need to be carefully evaluated by practitioners when adopting a contribution management process in practice.
Keywords: android; contribution; linux; management

Managing Corrective Actions to Closure in Open Source Software Test Process - Abdou, Tamer; Grogono, Peter; Kamthan, Pankaj (The 25th International Conference on Software Engineering and Knowledge Engineering (SEKE 2013), 2013)
In assessing test process maturity, one of the goals is to manage disciplinary issues. Managing corrective actions to closure is known to aid software quality assurance, in general, and testing process activities, in particular. In this paper, a framework for software testing assessment, namely OSS-TPA, that aims to evaluate corrective actions in OSS test process, is proposed. The OSS-TPA framework is based on earlier studies and relies on a conceptual model for test process activities in OSS development. Using success factors in OSS development, the relationship between the maturity of managing corrective actions and the adoption of OSS is investigated.
Keywords: open source software; software engineering; software quality; Software testing; Test Process Improvement.

The Maven Repository Dataset of Metrics, Changes, and Dependencies - Steven Raemaekers; van Deursen, Arie; Visser, Joost (10th Working Conference on Mining Software Repositories, 2013)
We present the Maven Dependency Dataset (MDD), containing metrics, changes and dependencies of 148,253 jar files. Metrics and changes have been calculated at the level of individual methods, classes and packages of multiple library versions. A complete call graph is also presented which includes call, inheritance, containment and historical relationships between all units of the entire repository. In this paper, we describe our dataset and the methodology used to obtain it. We present different conceptual views of MDD and we also describe limitations and data quality issues that researchers using this data should be aware of. http://data.3tu.nl/repository/uuid:68a0e837-4fda-407a-949e-a159546e67b6
Keywords: maven

Mining Developer Contribution in Open Source Software Using Visualization Techniques - Ben, Xu; Beijun, Shen; Weicheng, Yang (2013 Third International Conference on Intelligent System Design and Engineering Applications (ISDEA), 2013)
The research of developers' contribution is an important part of the software evolution area. It allows project owners to find potential long-term contributors earlier and helps the newcomers to improve their behaviors. In this paper, we examined the contribution characteristics of developers in open source environment based on visual analysis, and presented approaches from three aspects-influencing factors, time characteristics and region characteristics. Our analysis used data from github and revealed some regular patterns. We found that the code which newcomers started to contribute with more people engaged in would lead to less contribution in some degree. We also found that there's a relation between developers' early and later period contribution. In addition, developers from different regions were more likely to have dominant relationship. Our findings may provide some support for future research in the area of software evolution.
Keywords: github

Mining Source Code Repositories at Massive Scale using Language Modeling - Allamanis, Miltiadis; Sutton, Charles (10th Working Conference on Mining Software Repositories, 2013)
The tens of thousands of high-quality open source software projects on the Internet raise the exciting possibility of studying software development by finding patterns across truly large source code repositories. This could enable new tools for developing code, encouraging reuse, and navigating large projects. In this paper, we build the first giga-token probabilistic language model of source code, based on 352 million lines of Java. This is 100 times the scale of the pioneering work by Hindle et al. The giga-token model is significantly better at the code suggestion task than previous models. More broadly, our approach provides a new “lens” for analyzing software projects, enabling new complexity metrics based on statistical analysis of large corpora. We call these metrics data-driven complexity metrics. We propose new metrics that measure the complexity of a code module and the topical centrality of a module to a software project. In particular, it is possible to distinguish reusable utility classes from classes that are part of a program’s core logic based solely on general information theoretic criteria.

Misconceptions and Barriers to Adoption of FOSS in the U.S. Energy Industry - Kuechler, Victor; Jensen, Carlos; Bryant, Deborah (IFIP Advances in Information and Communication TechnologyOpen Source Software: Quality Verification, 2013)
In this exploratory study, we map the use of free and open source software (FOSS) in the United States energy sector, especially as it relates to cyber security. Through two surveys and a set of semi-structured interviews—targeting both developers and policy makers—we identified key stakeholders, organizations, and FOSS projects, be they rooted in industry, academia, or public policy space that influence software and security practices in the energy sector. We explored FOSS tools, common attitudes and concerns, and challenges with regard to FOSS adoption. More than a dozen themes were identified from interviews and surveys. Of these, drivers for adoption and risks associated with FOSS were the most prevalent. More specifically, the misperceptions of FOSS, the new security challenges presented by the smart grid, and the extensive influence of vendors in this space play the largest roles in FOSS adoption in the energy sector.

Modeling Practices in Open Source Software - Badreddin, Omar; Lethbridge, Timothy; Elassar, Maged (IFIP Advances in Information and Communication TechnologyOpen Source Software: Quality Verification, 2013)
It is widely accepted that modeling in software engineering increases productivity and results in better code quality. Yet, modeling adoption remains low. The open source community, in particular, remains almost entirely code centric. In this paper, we explore the reasons behind such limited adoption of modeling practices among open source developers. We highlight characteristics of modeling tools that would encourage their adoption. We propose Umple as a solution where both modeling and coding elements are treated uniformly. In this approach, models can be manipulated textually and code can be edited visually. We also report on the Umple compiler itself as a case study of an open source project where contributors, using the above approach, have and continue to routinely commit code and model over a number of years.

A Network of Rails: A Graph Dataset of Ruby on Rails and Associated Projects - Wagstrom, Patrick; Jergensen, Corey; Sarma, Anita (10th Working Conference on Mining Software Repositories, 2013)
Software projects, whether open source, proprietary, or a combination thereof, rarely exist in isolation. Rather, most projects build on a network of people and ideas from dozens, hundreds, or even thousands of other projects. Using the GitHub APIs it is possible to extract these relationships for millions of users and projects. In this paper we present a dataset of a large network of open source projects centered around Ruby on Rails. This dataset provides insight into the relationships between Ruby on Rails and an ecosystem involving 1116 projects. To facilitate understanding of this data in the context of relationships between projects, users, and their activities, it is provided as a graph database suitable for assessing network properties of the community and individuals within those communities and can be found at https://github.com/pridkett/gitminer-data-rails.

Open Source Community Processes: Implications on Micro and Macro Level - Koch, Stefan (it – Information Technology, 2013)
In this paper, we will discuss the existence and form of open source community processes, whether they differ between projects, and whether they have any implications on both micro and macro level. We will take a look at how different processes can impact the work and the resulting quality within projects, as well as on macro or project level outcomes like success or efficiency. We will also present as well as validate a research model to explain process adoption and implications.

An Open Source Monitoring Framework for Enterprise SOA - El Ioini, Nabil; Garibbo, Alessandro; Sillitti, Alberto; Succi, Giancarlo (IFIP Advances in Information and Communication TechnologyOpen Source Software: Quality Verification, 2013)
Web services monitoring is currently emerging as an effective way to trace faults in services at runtime. The lack of testing information provided by web services specifications was an indication that other methods need to be used to assess the quality of web services. This is mainly due to the fact that it is difficult to simulate the client infrastructure during testing of web services. Monitoring consists of inspecting services at runtime and taking adequate actions when unacceptable events occur. Monitoring could be performed by different stakeholders and could target different properties of services. Predominantly, monitoring is performed by service providers to manage their internal resources and balance their requests load. In our effort to improve the monitoring infrastructures, we propose a monitoring framework in which all the participants (services providers, services requestors) can contribute to monitoring and at the same time have direct access to the monitoring data. This paper describes a monitoring framework developed as part of NEXOF-RA project. The framework offers a set of capabilities for a collaborative monitoring of web services. The paper presents motivations, system design, implementation and usage of the framework.

Orion: A Software Project Search Engine with Integrated Diverse Software Artifacts - Bissyande, Tegawende F.; Thung, Ferdian; Lo, David; Jiang, Lingxiao; Reveillere, Laurent (2013 18th International Conference on Engineering of Complex Computer Systems (ICECCS), 2013)
What projects contain more than 10, 000 lines of code developed by less than 10 people and are still actively maintained with a high bug-fixing rate? To address the challenges for answering such enquiries, we develop an integrated search engine architecture that combines information from different types of software repositories from multiple sources. Our search engine facilitates the construction and execution of complex search queries using a uniform interface that transparently correlates different artifacts of project development and maintenance, such as source code information, version control systems metadata, bug tracking systems elements, and metadata on developer activities and interactions extracted from hosting platforms. We have built an extensible system with an initial capability of over 100, 000 projects collected from the web, featuring various software development artifacts. Using scenarios, we illustrate the benefits of such a search engine for different kinds of project seekers.
Keywords: flossmole cited

A Preliminary Analysis of Localization in Free Software: How Translations Are Performed - Reina, Laura Arjona; Gregorio Robles; Jesus M. Gonzalez-Barahona (IFIP Advances in Information and Communication TechnologyOpen Source Software: Quality Verification, 2013)
Software is more than just source code. There is a myriad of elements that compose a software project, among others documentation, translations, multimedia, artwork, marketing. In this paper, we focus on the translation efforts that free, libre, open source software (FLOSS) projects undergo to provide their software in multiple languages. We have therefore analyzed a large amount of projects for their support and procedures regarding translations, if they exist. Our results show that many, but not all, projects offer some type of support and specify some ways to those wanting to contribute. Usually, projects from a more traditional libre software domain are more prone to ease such tasks. However, there is no general way to contribute, as formats and procedures are often project-specific. We have identified as well a high number of translation-supporting tools, with many projects having their own one. All in all, information about how to contribute is the main factor for having a very internationalized application. Projects accepting and giving credit to contributing translators have high levels of internationalization, even if the process is rudimentary.

Preliminary steps toward a general theory of internet-based collective-action in digital information commons: Findings from a study of open source software projects - Charles Schweik; Robert English (International Journal of the Commons, 2013)
This paper presents some of the findings from a 5-year empirical study of FOSS (free/libre and open source software) commons, completed in 2011. FOSS projects are Internet-based common property regimes where the project source code is developed over the Internet. The resulting software is generally distributed with a license that provides users with the freedoms to access, use, read, modify and redistribute the software. In this study we used three different and very large datasets (approximately 107,000; 174,000 and 1400 cases respectively) with information on FOSS projects residing in Sourceforge.net, one of the largest, if not the largest, FOSS repository in the world. We employ various quantitative methods to uncover factors that lead some FOSS projects to ongoing collaborative success, while others become abandoned. After presenting some of our study’s results, we articulate the collaborative “story” of FOSS that emerged. We close the paper by discussing some key findings that can contribute to a general theory of Internet-based collective-action and FOSS-like forms of digital online commons.
Keywords: collaborative success and abandonment; common property regime; digital information commons; flossmole; Free/libre software; open source software; sourceforge; srda

Processes in Securing Open Architecture Software Systems - Walt Scacchi; Alspaugh, Thomas A. (Proceedings of the 2013 International Conference on Software and System Process, 2013)
Our goal is to identify and understand issues that arise in the development and evolution processes for securing open architecture (OA) software systems. OA software systems are those developed with a mix of closed source and open source software components that are configured via an explicit system architectural specification. Such a specification may serve as a reference model or product line model for a family of concurrently sustained OA system versions/variants. We employ a case study focusing on an OA software system whose security must be continually sustained throughout its ongoing development and evolution. We limit our focus to software processes surrounding the architectural design, continuous integration, release deployment, and evolution found in the OA system case study. We also focus on the role automated tools, software development support mechanisms, and development practices play in facilitating or constraining these processes through the case study. Our purpose is to identify issues that impinge on modeling (specification) and integration of these processes, and how automated tools mediate these processes, as emerging research problems areas for the software process research community. Finally, our study is informed by related research found in the prescriptive versus descriptive practice of these processes and tool usage in studies of conventional and open source software development projects.
Keywords: configuration; continuous software development; Open architecture; process integration; process modeling; security

Project Roles in the Apache Software Foundation: A Dataset - Squire, Megan (2013)
This paper outlines the steps in the creation and maintenance of a new dataset listing leaders of the various projects of the Apache Software Foundation (ASF). Included in this dataset are different levels of committers to the various ASF project code bases, as well as regular and emeritus members of the ASF, and directors and officers of the ASF. The dataset has been donated to the FLOSSmole project under an open source license, and is available for download (https://code.google.com /p/flossmole/downloads/detail?name=apachePeople2013-Jan.zip), or for direct querying via a database client.
Keywords: apache; dataset; roles

"Release Early, Release Often"? An Empirical Analysis of Release Strategy in Open Source Software Co-Creation - Chen, Wei; Krishnan, Vish; Zhu, Kevin (PACIS 2013 Proceedings, 2013)
“Release early, release often” is becoming a popular new product introduction strategy in open source software development. We study the influence of release strategies on the download market share of open source projects. Using a panel data set collected from Sourceforge.net, we find that while more frequent releases are associated with better subsequent download market share, the relationship is curvilinear. Too frequent releases could backfire due to the subtle effects on the demand and supply sides of open source software production. From the demand side, we find that releasing frequently may work less effectively in projects with higher adoption costs. From the supply side, fast releases may work less effectively in projects with weak community contributions. Even when the community contributions are strong, the restrictiveness of open source license moderates the effectiveness of releasing early and often. These results have implications for managing open source projects and research on open source software, open innovation, and software adoption.

A Replicable Infrastructure for Empirical Studies of Email Archives - Squire, Megan (3rd International Workshop on Replication in Empirical Software Engineering Research (RESER2013), 2013)
This paper describes a replicable infrastructure solution for conducting empirical software engineering studies based on email mailing list archives. Mailing list emails, such as those affiliated with free, libre, and open source software (FLOSS) projects, are currently archived in several places online, but each research team that wishes to study these email artifacts closely must design their own solution for collection, storage and cleaning of the data. Consequently, research results will be difficult to replicate, especially as the email archive for any living project will still be continually growing. This paper describes a simple, replicable infrastructure for the collection, storage, and cleaning of project email data and analyses.
Keywords: apache; cleaning; collection; couchdb; database; document-oriented database; email; lucene; mailing lists; nosql; replication; storage

Research on mining the online co mmunity: a case of Open Source Software community - Yuo, Lan (WSEAS Transactions on Computers, 2013)
The development of Open Source Software (OSS) projects is a process of collective innovation in the environment of online community. The paper addresses the challenge of efficiently mining data from OSS web repositories and building models to study OSS community features. Data collection for OSS community study is nontrivial since most OSS projects are develope d by distributed developers using web tools. We design a mining process which combines web mining and database mining together to identify, extract, filter and analyze data. We address and analyze the difficulty of mining OSS community data. Our work provides a general solution for researchers to implement advanced techniques, such as web mining, data mining, statistics, and algorithms to collect and analyze online community data.

The Role of Microblogging in OSS Knowledge Management - Lewis, Jonathan (IFIP Advances in Information and Communication TechnologyOpen Source Software: Quality Verification, 2013)
Given that microblogging has been shown to play a valuable role in knowledge management within companies, it is useful to understand how it is being used in relation to OSS. This project studies tweets related to 12 open source projects and keywords, ranging from web content management systems (CMSes) to general office applications. It found considerable differences in the content and exchange of tweets, especially between specialist products such as CMSes and office suites such as OpenOffice. Tweets concerning the more specialist projects tended to provide information rather than updates on the user’s current status. We found a high proportion of event-driven traffic for some CMS projects, and a lower proportion for the office products and groups of projects.
Keywords: twitter

A scalable crawler framework for FLOSS data - Yanzhen Zou; Bing Zie; Zhang, Lingxiao (Proceedings of the 5th Asia-Pacific Symposium on Internetware - Internetware '13, 2013)
Free / Libre / Open Source Software (FLOSS) data, such as bug reports, mailing lists and related webpages, contains valuable information for reusing open source software projects. Before conducting further experiment on FLOSS data, researchers often need to download these data into a local storage system. We refer to this pre-process as FLOSS data retrieval, which in many cases can be a challenging task. In this paper, we proposed a crawler framework to ease the process of FLOSS data retrieval. To cope with various types of FLOSS data scattered on the Internet, we designed the framework in a scalable manner where a crawler program can be easily plugged into the system to extend its functionality. Researchers can perform the retrieval process on datasets of various types and sources simply by adding new configurations to the system. We have implemented the framework and provided basic functions via web-based interfaces. We presented the usage of the system by a detailed case study where we retrieved various types of datasets related to Apache Lucene project using our framework.
Keywords: flossmole cited

A short report on WikiSym + OpenSym 2013 - Dirk Riehle (ACM SIGWEB Newsletter, 2013)
WikiSym + OpenSym 2013 is the 2013 Joint International Symposium on Open Collaboration, a conference for and by researchers and practitioners of open collaboration, which took place in Hong Kong on Aug 5-7, 2013.

Socio-technical Congruence in OSS Projects: Exploring Conway’s Law in FreeBSD - Syeed, M.M. Mahbubul; Hammouda, Imed (IFIP Advances in Information and Communication TechnologyOpen Source Software: Quality Verification, 2013)
Software development requires effective communication, coordination and collaboration among developers working on interdependent modules of the same project. The need for coordination is even more evident in open source projects where development is often more dispersed and distributed. In this paper, we study the match between the coordination needs established by the technical domain (i.e. source code) and the actual coordination activities carried out by the development team, such hypothetical match is also known as socio-technical congruence. We carry out our study by empirically examining Conway’s law in FreeBSD project. Our study shows that the congruence measure is significantly high in FreeBSD and that the congruence value remains stable as the project matured.

Studying the laws of software evolution in a long-lived FLOSS project - Jesus M. Gonzalez-Barahona; Gregorio Robles; Herraiz, Israel; Ortega, Felipe (Journal of Software: Evolution and Process, 2013)
Some free, open-source software projects have been around for quite a long time, the longest living ones dating from the early 1980s. For some of them, detailed information about their evolution is available in source code management systems tracking all their code changes for periods of more than 15 years. This paper examines in detail the evolution of one of such projects, glibc, with the main aim of understanding how it evolved and how it matched Lehman's laws of software evolution. As a result, we have developed a methodology for studying the evolution of such long-lived projects based on the information in their source code management repository, described in detail several aspects of the history of glibc, including some activity and size metrics, and found how some of the laws of software evolution may not hold in this case.

Tools in Mining Software Repositories - Chaturvedi, K.K.; Sing, V.B.; Singh, Prashast (2013 13th International Conference on Computational Science and Its Applications (ICCSA), 2013)
Mining software repositories (MSR) is an important area of research. An international workshop on MSR has been established under the umbrella of international conference on software engineering (ICSE) in year 2004. The quality papers received and presented in the workshop has led to initiate full-fledged conference which purely focuses on issues related to mining software engineering data since 2007. This paper is the result of reviewing all the papers published in the proceedings of the conferences on Mining Software Repositories (MSR) and in other related conference/journals. We have analyzed the papers that contained experimental analysis of software projects related to data mining in software engineering. We have identified the data sets, techniques and tools used/ developed/ proposed in these papers. More than half of the papers are involved in the task accomplished by building or using the data mining tools to mine the software engineering data. It is apparent from the results obtained by analyzing these papers that MSR authors process the raw data which in general publicly available. We categorizes different tools used in MSR on the basis of newly developed, traditional data mining tools, prototype developed and scripts. We have shown the type of mining task that has been performed by using these tools along with the datasets used in these studies.

Towards a Reference Model on How to Utilise Open Standards in Open Source Projects: Experiences Based on Drupal - Andersson, Stefan; Feist, Jonas; Gustavsson, Tomas; Strindberg, Henrik; Gamalielsson, Jonas; Lundell, Björn; Grahn, Alexander (IFIP Advances in Information and Communication TechnologyOpen Source Software: Quality Verification, 2013)
It is known that standards implemented in Open Source software (OSS) can promote a competitive market, reduce the risk for lock-in and improve interoperability, whilst there is limited knowledge concerning the relationship between standards and their implementations in OSS. In this paper we report from an ongoing case study conducted in the context of the ORIOS (Open Source software Reference Implementations of Open Standards) project in which influences between OSS communities and software standard communities are investigated. The study focuses on the Drupal project and three of its implemented standards (RDFa, CMIS, and OpenID).

Towards base rates in software analytics - Bruntink, Magiel (Science of Computer Programming, 2013)
Nowadays a vast and growing body of open source software (OSS) project data is publicly available on the internet. Despite this public body of project data, the field of software analytics has not yet settled on a solid quantitative base for basic properties such as code size, growth, team size, activity, and project failure. What is missing is a quantification of the base rates of such properties, where other fields (such as medicine) commonly rely on base rates for decision making and the evaluation of experimental results. The lack of knowledge in this area impairs both research activities in the field of software analytics and decision making on software projects in general. This paper contributes initial results of our research towards obtaining base rates using the data available at Ohloh (a large-scale index of OSS projects). Zooming in on the venerable ‘lines of code’ metric for code size and growth, we present and discuss summary statistics and identify further research challenges.
Keywords: ohloh

Trends in Free, Libre, Open Source Software Communities: From Volunteers to Companies / Aktuelle Trends in Free-, Libre-, und Open-Source-Software-Gemeinschaften: Von Freiwilligen zu Unternehmen - Jesus M. Gonzalez-Barahona; Gregorio Robles (it - Information Technology, 2013)
The first free/libre/open source software (FLOSS) development communities were composed almost exclusively of volunteers. They were individuals who, despite their affiliation, contributed to the project on their own. They decided which project to join, and their contributions were personal in nature, even when in some cases they were employees of companies with some interests in the project. GNU, the first of such communities, and some others that emerged during the late 1980s and 1990s, followed this pattern. During the 1990s corporate interests started to have a role in some FLOSS communities. Companies hired people from those communities to gain influence, or tasked their employees to contribute to them, again with the idea of influencing their decisions. During the 2000s, corporate communities, in which companies are first-class citizens, have emerged, changing the rules and redefining the role of volunteers and non-affiliated individuals. However, the role of developers, with independence of the company for which they work, is still important even in these communities. This paper addresses this transition from volunteer-based to company-based development communities, and explores the structure and behavior of the latter.

Understanding How Companies Interact with Free Software Communities - Jesus M. Gonzalez-Barahona; Izquierdo-Cortazar, Daniel; Maffulli, Stefano; Gregorio Robles (IEEE Software, 2013)
When free, open source software development communities work with companies that use their output, it's especially important for both parties to understand how this collaboration is performing. The use of data analytics techniques on software development repositories can improve factual knowledge about performance metrics.

Understanding the Evolution of Type-3 Clones: An Exploratory Study - Ripon K. Saha; Chanchal K. Roy; Kevin A. Schneider; Perry, Dewayne E. (10th Working Conference on Mining Software Repositories, 2013)
Understanding the evolution of clones is important for both understanding the maintenance implications of clones and for building a robust clone management system. To this end, researchers have already conducted a number of studies to analyze the evolution of clones, mostly focusing on Type-1 and Type-2 clones. However, although there are a significant number of Type-3 clones in software systems, we know a little how they actually evolve. In this paper, we perform an exploratory study on the evolution of Type-1, Type-2, and Type-3 clones in six open source software systems written in two different programming languages and compare the result with a previous study to better understand the evolution of Type-3 clones. Our results show that although Type-3 clones are more likely to change inconsistently, the absolute number of consistently changed Type-3 clone classes is greater than that of Type-1 and Type-2. Type-3 clone classes also have a lifespan similar to that of Type-1 and Type-2 clones. In addition, a considerable number of Type-1 and Type-2 clones convert into Type-3 clones during evolution. Therefore, it is important to manage type-3 clones properly to limit their negative impact. However, various automated clone management techniques such as notifying developers about clone changes or linked editing should be chosen carefully due to the inconsistent nature of Type-3 clones.

Using Citation Influence to Predict Software Defects - Wei Hu; Kenny Wong (10th Working Conference on Mining Software Repositories, 2013)
The software dependency network reflects structure and the developer contribution network reflects process. Previous studies have used social network properties over these networks to predict whether a software component is defect-prone. However, these studies do not consider the strengths of the dependencies in the networks. In our approach, we use a citation influence topic model to determine dependency strengths among components and developers, analyze weak and strong dependencies separately, and apply social network properties to predict defect-prone components. In experiments on Eclipse and NetBeans, our approach has higher accuracy than prior work.
Keywords: eclipse; netbeans; social network

Using Developer Interaction Data to Compare Expertise Metrics - Robbes, Romain; Rothlisberger, David (10th Working Conference on Mining Software Repositories, 2013)
The expertise of a software developer is said to be a crucial factor for the development time required to complete a task. Even if this hypothesis is intuitive, research has not yet quantified the effect of developer expertise on development time. A related problem is that the design space for expertise metrics is large; out of the various automated expertise metrics proposed, we do not know which metric most reliably captures expertise. What prevents a proper evaluation of expertise metrics and their relation with development time is the lack of data on development tasks, such as their precise duration. Fortunately, this data is starting to become available in the form of growing developer interaction repositories. We show that applying MSR techniques to these developer interaction repositories gives us the necessary tools to perform such an evaluation.

Using software analytics to understand how companies interact in free software communities - Gonzalez-Barahona, Jesus; Izquierdo, Daniel; Maffulli, Stefano; Gregorio Robles (IEEE Software, 2013)
Free, open source software development communities may become large and complex. They may also be a focus of interest for competing companies relying on their outcomes, with their employees joining the development and maintenance effort. In those cases it is specially important for both companies and communities to understand how this collaboration is working, and how it matches their policies and expectations. In this paper we show two cases (OpenStack and WebKit) which we have studied using analytics techniques on the data obtained from their software development repositories. From them, we conclude that analytics on this data can improve the factual knowledge about how development communities are performing in aspects which are of interest to companies, and fundamental to ensure transparency and fairness.
Keywords: openstack; webkit

Who Does What during a Code Review? Datasets of OSS Peer Review Repositories - Kazuki Hamasaki; Raula Gaikovina Kula; Norihiro Yoshida; A. E. Camargo Cruz; Kenji Fujiwara; Hajimu Iida (10th Working Conference on Mining Software Repositories, 2013)
We present four datasets that are focused on the general roles of OSS peer review members. With data mined from both an integrated peer review system and code source repositories, our rich datasets comprise of peer review data that was automatically recorded. Using the Android project as a case study, we describe our extraction methodology, the datasets and their application used for three separate studies. Our datasets are available online at http://sdlab.naist.jp/reviewmining/
Keywords: android; case study; code review; data set; peer review; roles; source code

Why So Complicated? Simple Term Filtering and Weighting for Location-Based Bug Report Assignment Recommendation (10th Working Conference on Mining Software Repositories, 2013)
Large software development projects receive many bug reports and each of these reports needs to be triaged. An important step in the triage process is the assignment of the report to a developer. Most previous eorts towards improving bug report assignment have focused on using an activity-based approach. We address some of the limitations of activity-based approaches by proposing a two-phased location-based approach where bug report assignment recommendations are based on the predicted location of the bug. The proposed approach utilizes a noun extraction process on several information sources to determine bug location information and a simple term weighting scheme to provide a bug report assignment recommendation. We found that by using a location-based approach, we achieved an accuracy of 89.41% and 59.76% when recommending ﬁve developers for the Eclipse and Mozilla projects, respectively.
Keywords: bug; bug report assignment; eclipse; File Activity Histories; Mining Software Artifacts; mozilla; Named Entity Recognition; POS Filtering

Will My Patch Make It? And How Fast?: Case Study on the Linux Kernel - Yujuan Jiang; Adams, Bram; Daniel M. German (10th Working Conference on Mining Software Repositories, 2013)
The Linux kernel follows an extremely distributed reviewing and integration process supported by 130 developer mailing lists and a hierarchy of dozens of Git repositories for version control. Since not every patch can make it and of those that do, some patches require a lot more reviewing and integration effort than others, developers, reviewers and integrators need support for estimating which patches are worthwhile to spend effort on and which ones do not stand a chance. This paper cross- links and analyzes eight years of patch reviews from the kernel mailing lists and committed patches from the Git repository to understand which patches are accepted and how long it takes those patches to get to the end user. We found that 33% of the patches makes it into a Linux release, and that most of them need 3 to 6 months for this. Furthermore, that patches developed by more experienced developers are more easily accepted and faster reviewed and integrated. Additionally, reviewing time is impacted by submission time, the number of affected subsystems by the patch and the number of requested reviewers.

Adoption of free/libre open source software in public organizations: factors of impac - Rossi, Bruno; Russo, Barbara; Succi, Giancarlo (Information Technology & People, 2012)
Purpose – In this paper the authors aim to investigate the importance of factors for the adoption of free/libre open source software (FLOSS) in the public sector. They seek to evaluate how different factors impact during the initiation and implementation phases of the adoption process. Design/methodology/approach – The authors base the methodological approach on two exploratory case studies with a contrasting result logic. They build a multi-level framework grounded both on literature review, and feedback from stakeholders. They then apply the framework to two case studies to better frame the findings. They consider phases of adoption (initiation, implementation) and the levels of adoption (technological, organizational, environmental, individual). Findings – In the case studies, the authors found the importance of a strong and decision-centric management board to give the impulse for the initiation phase of the process. As perceived by the stakeholders, a strong governmental support is of paramount importance to increase the adoption at the public level, although in the case studies examined the initiation stage started from the impulse of a championing management. Both case studies passed the initiation phase successfully. Continuous employees' training, organizational objectives consensus, and business process reengineering have been found important for the implementation phase. In the case study in which these factors were not in place, the implementation phase of adoption failed. Environmental factors – although relevant for the initiation of the adoption process – are less significant during the actual implementation of the adoption process, as the contrasting result logic from the case studies shows. Research limitations/implications – The study refers to two public organizations in a specific environmental setting. No causality among factors has been inferred. Quantitative objective data have been used to determine the success of adoption, for qualitative data multiple sources have been used when possible to limit threats to validity. Practical implications – The framework can be used by stakeholders in public organizations to better frame their adoption strategies and to compare results across institutions. Lessons learnt from the case studies can be useful to drive future adoptions of FLOSS. Originality/value – The framework combines phases of adoption and levels making it possible to frame the analysis of the case studies. It has been operationalized with a set of metrics, and with a protocol for the case studies to increase replicability value.

Analyzing and mining a code search engine usage log - Bajracharya, Sushil Krishna; Lopes, Cristina Videira (Empirical Software Engineering, 2012)
This paper presents an analysis of a year long usage log of Koders, the first commercially available Internet-Scale code search engine (http://www.koders.com). The usage log comprises about ten million activities from more than three million users. Analysis of the usage data shows that despite of attracting a large number of visitors, Koders has a very sparse usage and that it lacks regular usage from many of its users. When compared to Web search, search behavior in Koders showed many similar patterns. A topic modeling analysis of the usage data shows what topics users of Koders are looking for. Observations on the prevalence of these topics among the users, and observations on how search and download activities vary across topics, lead to the conclusion that users who find code search engines usable are those who already know to a high level of specificity what to look for. This paper also presents a general categorization of these topics that provides insights on the different ways code search engine users express their queries. It identifies various forms of queries in Koders’s log and the kinds of results addressed by the queries. It also provides several suggestions for improvements in code search engines based on the analysis of usage, topics, and query forms. The work presented in this paper is the first of its kind that reveals several insights on the usage of an Internet-Scale code search engine.
Keywords: code search; koders; search; search engine; topics

Automated topic naming: supporting cross-project analysis of software maintenance activities - Hindle, Abram; Ernst, Neil A.; Godfrey, Michael W.; Mylopoulos, John (Empirical Software Engineering, 2012)
Software repositories provide a deluge of software artifacts to analyze. Researchers have attempted to summarize, categorize, and relate these artifacts by using semi-unsupervised machine-learning algorithms, such as Latent Dirichlet Allocation (LDA). LDA is used for concept and topic analysis to suggest candidate word-lists or topics that describe and relate software artifacts. However, these word-lists and topics are difficult to interpret in the absence of meaningful summary labels. Current attempts to interpret topics assume manual labelling and do not use domain-specific knowledge to improve, contextualize, or describe results for the developers. We propose a solution: automated labelled topic extraction. Topics are extracted using LDA from commit-log comments recovered from source control systems. These topics are given labels from a generalizable cross-project taxonomy, consisting of non-functional requirements. Our approach was evaluated with experiments and case studies on three large-scale Relational Database Management System (RDBMS) projects: MySQL, PostgreSQL and MaxDB. The case studies show that labelled topic extraction can produce appropriate, context-sensitive labels that are relevant to these projects, and provide fresh insight into their evolving software development activities.
Keywords: LDA; maxdb; mysql; postgresql; topics

Binoculars: Comprehending Open Source Projects through Graphs - Syeed, M.M. Mahbubul (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Comprehending Open Source Software (OSS) projects requires dealing with huge historical information stored in heterogeneous repositories, such as source code versioning systems, bug tracking system, mailing lists, and revision history logs. In this paper, we present Binoculars, a prototype tool which aims to provide a platform for graph based visualization and exploration of OSS projects. We describe the issues need to be addressed for the design and implementation of a graph based tool and distill lessons learned for future guideline.

Carrots and Rainbows: Motivation and Social Practice in Open Source Software Development - Georg von Krogh; Stefan Haefliger; Sebastian Spaeth; Martin W. Wallin (Management Information Systems Quarterly, 2012)
Open source software (OSS) is a social and economic phenomenon that raises fundamental questions about the motivations of contributors to information systems development. Some developers are unpaid volunteers who seek to solve their own technical problems, while others create OSS as part of their employment contract. For the past 10 years, a substantial amount of academic work has theorized about and empirically examined developer motivations. We review this work and suggest considering motivation in terms of the values of the social practice in which developers participate. Based on the social philosophy of Alasdair MacIntyre, we construct a theoretical framework that expands our assumptions about individual motivation to include the idea of a long-term, value-informed quest beyond short-term rewards. This motivation–practice framework depicts how the social practice and its supporting institutions mediate between individual motivation and outcome. The framework contains three theoretical conjectures that seek to explain how collectively elaborated standards of excellence prompt developers to produce high-quality software, change institutions, and sustain OSS development. From the framework, we derive six concrete propositions and suggest a new research agenda on motivation in OSS.

Citizen Engineering: Evolving OSS Practices to Engineering Design and Analysis - Zhai, Zhi; Kijewski-Correa, Tracy; Kareem, Ashan; Hachen, David; Madey, Gregory (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Open Source Software (OSS) development has much in common with concepts such as crowdsourcing, citizen science, collective intelligence, human-based computation, and what we call “Citizen Engineering (CE)”. We report on several pilot projects that apply these shared principles of OSS development to engineering activities beyond software engineering. CE models harness human computing power from open communities, which commonly consist of a cohort of geographically and/or institutionally scattered citizens - professionals or amateurs - to collaboratively solve real-world problems. In most cases, the problems targeted are challenging to computers, but manageable or trivial to human intelligence. In these systems, while humans play fundamental roles, whether they are project architects or problem solvers, the implementation of CE is greatly facilitated by the advance of information technology, particularly the Internet, considered as "creative mode of user interactivity, not merely a medium between messages and people" [10]. In this paper, we characterize existing citizen engineering practices into 6 major categories, followed by a discussion of 4 ongoing projects, aiming to provide new perspectives and insights for achieving successful CE project designs.

Clones: what is that smell? - Rahman, Foyzur; Christian Bird; Devanbu, Premkumar (Empirical Software Engineering, 2012)
Clones are generally considered bad programming practice in software engineering folklore. They are identified as a bad smell (Fowler et al. 1999) 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 the relationship between cloning and defect proneness. For the four medium to large open source projects that we studied, 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. Third, we find little evidence that clones with more copies are actually more error prone. Fourth, we find little evidence to support the claim that clone groups that span more than one file or directory are more defect prone than collocated clones. Finally, we find that developers do not need to put a disproportionately higher effort to fix clone dense bugs. Our findings do not support the claim that clones are really a “bad smell” (Fowler et al. 1999). Perhaps we can clone, and breathe easily, at the same time.

A Comprehensive Study of Software Forks: Dates, Reasons and Outcomes - Gregorio Robles; González-Barahona, Jesús M. (IFIP Advances in Information and Communication Technology (OSS 2012), 2012)
Summary. In general it is assumed that a software product evolves within the authoring company or group of developers that develop the project. However, in some cases different groups of developers make the software evolve in different directions, a situation which is commonly known as a fork. In the case of free software, although forking is a practice that is considered as a last resort, it is inherent to the four freedoms. This paper tries to shed some light on the practice of forking. Therefore, we have identified significant forks, several hundreds in total, and have studied them in depth. Among the issues that have been analyzed for each fork is the date when the forking occurred, the reason of the fork, and the outcome of the fork, i.e., if the original or the forking project are still developed. Our investigation shows, among other results, that forks occur in every software domain, that they have become more frequent in recent years, and that very few forks merge with the original project.
Keywords: forking; forks; free software; Legal; open source; social; software evolution; sustainability

A Conceptual Framework for Open Source Software Test Process - Abdou, Tamer; Grogono, Peter; Kamthan, Pankaj (2012 IEEE 36th IEEE Annual Computer Software and Applications Conference Workshops (COMPSACW), 2012)
The broad acceptance and use of Open Source Software (OSS) has underscored the necessity of investigating the means of assuring their quality. With the aim of identifying an OSS test process, three well-known OSS projects, namely Apache HTTP server, Mozilla Web browser, and NetBeans IDE were studied. In these studies, three activities were found similar to the activities of the ISO/IEC Test Process Standard. However, major differences were observed in tasks related to each of the test process activities. To systematize the OSS test process, an Open Source Software Test Process Framework (OSS-TPF) is proposed. The alignment of OSS-TPF with the ISO/IEC Test Process Standard is illustrated.

Content classification of developer emails - Bacchelli, Alberto; Dal Sasso, Tommaso; D'Ambros, Marco; Lanza, Michele (Proceedings of the 34th IEEE/ACM International Conference On Software Engineering (ICSE 2012), 2012)
Emails related to the development of a software system contain information about design choices and issues encountered during the development process. Exploiting the knowledge embedded in emails with automatic tools is challenging, due to the unstructured, noisy and mixed language nature of this communication medium. Natural language text is often not well-formed and is interleaved with languages with other syntaxes, such as code or stack traces. We present an approach to classify email content at line level. Our technique classifies email lines in five categories (i.e., text, junk, code, patch, and stack trace) to allow one to subsequently apply ad hoc analysis techniques for each category. We evaluated our approach on a statistically significant set of emails gathered from mailing lists of four unrelated open source systems.
Keywords: email; Emails; Empirical software engineering; mailing list; natural language; Unstructured Data Mining

Describing the Software Forge Ecosystem - Squire, Megan; Williams, David (45th Hawai'i International Conference on System Sciences, 2012)
Code forges are online software systems that are designed to support teams doing software development work. There have been few if any attempts in the research literature to describe the web of people, projects, and tools that make up the free, libre, and open source (FLOSS) forge ecosystem. The main contributions of this paper are (1) to introduce a classification of FLOSS-oriented forges according to their characteristics; (2) to describe the forge-level and project-level data and artifacts currently available at each FLOSS forge; (3) to show various patterns already discovered in the FLOSS forge ecosystem, such as timelines of creation or arrangements by size or feature; (4) to make some recommendations to forge providers and data collectors about how to expose the structure and information in the forges; and (5) to describe the effort needed to extend our publicly- available information about the FLOSS forge ecosystem into the future.
Keywords: features; FLOSS; forge; hosting; metrics

Designing Secure Systems Based on Open Architectures with Open Source and Closed Source Components - Walt Scacchi; Alspaugh, Thomas (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
The development and evolution of secure open architecture systems has received insufficient consideration. Such systems are composed of both open source and closed software software components subject to different security requirements in an architecture in which evolution can occur by evolving existing components, replacing them, or refactoring their interfaces, interconnections and configuration. But this may result in possible security requirements conflicts and organizational liability for failure to fulfill security obligations. We are developing an approach for understanding and modeling software security requirements as security licenses, as well as for analyzing conflicts among groups of such licenses in realistic system contexts and for guiding the acquisition, integration, or development of systems with open source components in such an environment. Consequently, this paper reports on our efforts to extend our existing approach to specifying and analyzing software Intellectual Property (IP) licenses to now address software security licenses that can be associated with secure OA systems.

Developing an h-index for OSS developers - A. Capiluppi; Serebrenik, A.; Youssef, A. (2012 9th IEEE Working Conference on Mining Software Repositories (MSR), 2012)
The public data available in Open Source Software (OSS) repositories has been used for many practical reasons: detecting community structures; identifying key roles among developers; understanding software quality; predicting the arousal of bugs in large OSS systems, and so on; but also to formulate and validate new metrics and proof-of-concepts on general, non-OSS specific, software engineering aspects. One of the results that has not emerged yet from the analysis of OSS repositories is how to help the “career advancement” of developers: given the available data on products and processes used in OSS development, it should be possible to produce measurements to identify and describe a developer, that could be used externally as a measure of recognition and experience. This paper builds on top of the h-index, used in academic contexts, and which is used to determine the recognition of a researcher among her peers. By creating similar indices for OSS (or any) developers, this work could help defining a baseline for measuring and comparing the contributions of OSS developers in an objective, open and reproducible way.

Discussion on the Problems to be Solved toward the Migration to OSS Productivity Software in the Business Enterprises - Iio, Jun; Ogawa, Tomotaka (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
In recent years, there is a tendency to migrate from proprietary productivity software to open-source productivity software, especially in government offices and municipal offices. ODPG (OpenOffice.org & OpenDocument Format Promotion Group, Japan) is an organization founded in order to promote the migration to the OSS productivity software in private enterprises as well. In the case evaluation work group of ODPG, business solutions about use of OpenOffice.org have been discussed many times, for the purpose of supporting the migration to OpenOffice.org, by collecting and feeding back the information of case studies useful for the member companies. This paper reports several subjects and solutions, such as promotion strategy for OpenOffice.org to be widely used, the problem in file exchange with the other stakeholders, preparation of use environment, and security issues, which were discussed in the work group.

Do More Experienced Developers Introduce Fewer Bugs? - Izquierdo-Cortázar, Daniel; Gregorio Robles; González-Barahona, Jesús M. (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Developer experience is a common matter of study in the software maintenance and evolution research literature. However it is still not well understood if less experienced developers are more prone to introduce errors in the source code than their more experienced colleagues. This paper aims to study the relationships between experience and the bug introduction ratio using the Mozilla community as case of study. As results, statistical differences among developers with different levels of experience has not been observed, when the expected result would have been the opposite1.
Keywords: mercurial; mozilla; scm; source code analysis

Does OSS Affect E-Government Growth? An Econometric Analysis on the Impacting Factors - Lakka, Spyridoula; Stamati, Teta; Martakos, Draculis (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Inspired by the OSS values, an increasing number of different forms of open initiatives have come to the fore. In the context of eGovernment the notion of open government has met wide acceptance among nations and became closely related to one of its goals. Open government shares with OSS the notions of collaboration, participation and transparency and many actions towards OSS into eGovernment reform policies, have been recorded worldwide. The study investigates the relationship between OSS growth and eGovernment. A theoretical framework of the theories of institutionalism, growth and human capital is proposed as the guiding theoretical lens to identify possible influencing factors that together with OSS are evaluated for their magnitude of impact on eGovernment growth across different economic environments.
Keywords: eGovernment adoption; growth theory; human capital theory; institutionalism

The Effect of Open Source Licensing on the Evolution of Business Strategy - Noda, Tetsuo; Tansho, Terutaka; Coughlan, Shane (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
This paper explores how the approach underlying Open Source development has encouraged a greater sharing of knowledge in related business and legal affairs, and subsequently leads to the emergence of Open Source-driven collaboration by enterprises to address challenges. We use an Economic approach to propose a theoretical framework for Open Source business analysis and provide a defined sample of real-world developments to support its initial findings. We conclude that the need to develop effective Open Source governance solutions has led to widespread collaboration regarding business and legal challenges by stakeholders in the field, and that this collaboration will increase to improve efficiency as the market matures.

The Effects of Diversity in Global, Distributed Collectives: A Study of Open Source Project Success - Daniel, Sherae L.; Ritu Agarwal; Stewart, Katherine J. (Information Systems Research, 2012)
Diversity is a defining characteristic of global collectives facilitated by the Internet. Though substantial evidence suggests that diversity has profound implications for a variety of outcomes including performance, member engagement, and withdrawal behavior, the effects of diversity have been predominantly investigated in the context of organizational workgroups or virtual teams. We use a diversity lens to study the success of non-traditional virtual work groups exemplified by open source software (OSS) projects. Building on the diversity literature, we propose that three types of diversity (separation, variety and disparity) influence two critical outcomes for OSS projects: community engagement and market success. We draw on the OSS literature to further suggest that the effects of diversity on market success are moderated by the application development stage. We instantiate the operational definitions of three forms of diversity to the unique context of open source projects. Using archival data from 357 projects hosted on SourceForge, we find that disparity diversity, reflecting variation in participants‘ contribution-based reputation, is positively associated with success. The impact of separation diversity, conceptualized as culture and measured as diversity in the spoken language and country of participants, has a negative impact on community engagement but an unexpected positive effect on market success. Variety diversity, reflected in dispersion in project participant roles, positively influences community engagement and market success. The impact of diversity on market success is conditional on the development stage of the project. We discuss how the study‘s findings advance the literature on antecedents of OSS success, expand our theoretical understanding of diversity, and present the practical implications of the results for managers of distributed collectives.
Keywords: diversity; global collectives; open source software

Emerging Hackerspaces – Peer-Production Generation - Moilanen, Jarkko (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
This paper describes a peer-production movement, the hackerspace movement, its members and values. The emergence of hackerspaces, fablabs and makerspaces is changing how hacker communities and other like-minded communities function. Thus, an understanding of the nature of hackerspaces helps in detailing the features of contemporary peer-production. Building on previous work on 'fabbing', two different sets of results are presented: (1) empirical observations from a longitudinal study of hackerspace participants; and (2) a theoretical description of hacker generations as a larger context in which peer-production can be located. With regard to (1), research data has been collected through prolonged observation of hackerspace communities and two surveys.
Keywords: COMMUNITY; fabbing; fablab; hackerspace; makerspace; MOTIVATION; movement; open source; peer-production; Survey; sustainability

An Empirical Study of Volunteer Members' Perceived Turnover in Open Source Software Projects - Yu, Yiqing; Benlian, Alexander; Hess, Thomas (45th Hawai'i International Conference on System Sciences, 2012)
Turnover of volunteer members and the ensuing instability bring about severe problems to open source software (OSS) projects. To better understand it, we based our study on Herzberg ́s two-factor theory to investigate the influence of hygiene factors on volunteer members ́ dissatisfaction and perceived turnover. After empirically testing the research model, we found shortcomings in project regulation and administration are the key reason for volunteer members ́ dissatisfaction, followed by future rewards and personal needs for software functionalities. By contrast, a possible lack of supportive working relationship among OSS developers was not found to be a trigger for developer dissatisfaction. Dissatisfaction was confirmed to be a significant predictor of perceived turnover. The results demonstrates generalized hygiene factors cannot unreflectively be transferred into the OSS context because volunteer members ́ personal expectation has a weaker influence on perceived turnover than objective attributes of OSS project. Our study further makes suggestions for project administrators.
Keywords: developers; launchpad; sourceforge; Survey

The evolution of Java build systems - McIntosh, Shane; Adams, Bram; Hassan, Ahmed E. (Empirical Software Engineering, 2012)
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. However, a firm understanding of build system aging processes is needed in order to allow project managers to allocate personnel and resources to build system maintenance tasks effectively, and reduce the build maintenance overhead on regular development activities. In this paper, we study the evolution of build systems based on two popular Java build languages (i.e., ANT and Maven) from two perspectives: (1) a static perspective, where we examine the complexity of build system specifications using software metrics adopted from the source code domain; and (2) a dynamic perspective, where the complexity and coverage of representative build runs are measured. Case studies of the build systems of six open source build projects with a combined history of 172 releases show that build system and source code size are highly correlated, with source code restructurings often requiring build system restructurings. Furthermore, we find that Java build systems evolve dynamically in terms of duration and recursive depth of the directory hierarchy.
Keywords: ant; build; maven; scm; source code analysis

Examining Turnover in Open Source Software Projects Using a Logistic Hierarchical Linear Modeling Approach - Sharma, P.N.; Hulland, J.; Daniel, S. (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Developer turnover in open source software projects is a critical and insufficiently researched problem. Previous research has focused on understanding the developer motivations to contribute using either the individual developer perspective or the project perspective. In this exploratory study we argue that because the developers are embedded in projects it is imperative to include both perspectives. We analyze turnover in open source software projects by including both individual developer level factors, as well as project specific factors. Using the Logistic Hierarchical Linear Modeling approach allows us to empirically examine the factors influencing developer turnover and also how these factors differ among developers and projects.
Keywords: Logistic Hierarchical Linear Modeling; sourceforge; turnover

Exploring the Barriers and Enablers to the Use of Open Educational Resources by University Academics in Africa - Percy, Tanya; Van Belle, Jean-Paul (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Considerable effort has gone into Open Educational Resource (OER) initiatives in the past decade. These initiatives have created free, high quality educational resources for everyone and anyone to use. However, these open and free resources appear to remain largely unused by university academics on the educationally resource-poor African continent. The objectives of the research study are to explore the inhibitors and enablers are experienced by academics that use OER, and what barriers prevent academics from using OER. The sample consists of academics from East, West and Southern Africa. Information was gathered by means of a survey questionnaire. A modified version of the Unified Theory of Acceptance and Use of Technology model was used to identify the influence of certain factors on a user’s intention to adopt OER. Some of the key findings indicate that Performance Expectancy and Effort Expectancy have a positive effect on a user's Behavioural Intention to use OER, and the latter has a strong influence on the Actual Use of OER. Facilitating Conditions do not have a statistically significant impact. Additionally, significant differences were found in the barriers which users and potential users of OER have identified as either limiting their current use of OER, or negatively affecting their intention to use OER. These barriers include discovery, relevance, context and individual resources. Addressing these factors could lead to a more widespread adoption of Open Educational Resources in Africa and, consequently, more pervasive and higher quality educational opportunities.

Exploring the Role of Commercial Stakeholders in Open Source Software Evolution - Capiluppi, Andrea; Stol, Klaas-Jan; Boldyreff, Cornelia (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
It has been lately established that a major success or failure factor of an OSS project is whether or not it involves a commercial company, or more extremely, when a project is managed by a commercial software corporation. As documented recently, the success of the Eclipse project can be largely attributed to IBM’s project management, since the upper part of the developer hierarchy is dominated by its staff. This paper reports on the study of the evolution of three different Open Source (OSS) projects — the Eclipse and jEdit IDEs and the Moodle e-learning system — looking at whether they have benefited from the contribution of commercial companies. With the involvement of commercial companies, it is found that OSS projects achieve sustained productivity, increasing amounts of output produced and intake of new developers. It is also found that individual and commercial contributions show similar stages: developer intake, learning effect, sustained contributions and, finally, abandonment of the project. This preliminary evidence suggests that a major success factor for OSS is the involvement of a commercial company, or more radically, when project management is in hands of a commercial entity.

Exploring the Role of Outside Organizations in Free / Open Source Software Projects - Forrest, Darren; Jensen, Carlos; Mohan, Nitin; Davidson, Jennifer (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Free/Open Source Software (FOSS) projects have a reputation for being grass-roots efforts driven by individual contributors volunteering their time and effort. While this may be true for a majority of smaller projects, it is not always the case for large projects. As projects grow in size, importance and complexity, many come to depend on corporations, universities, NGO’s and governments, for support and contributions, either financially or through seconded staff. As outside organizations get involved in projects, how does this affect their governance, transparency and direction? To study this question we gathered bug reports and commit logs for GCC and the Linux Kernel. We found that outside organizations contribute a majority of code but rarely participate in bug triaging. Therefore their code does not necessarily address the needs of others and may distort governance and direction. We conclude that projects should examine their dependence on outside organizations
Keywords: bug reports; commit; Community sustainability; Contributor affiliation; gcc; governance; linux kernel; Participation metrics

Forking the Commons: Developmental Tensions and Evolutionary Patterns in Open Source Software - Gençer, Mehmet; Özel, Bülent (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Open source software (OSS) presents opportunities and challenges for developers to exploit its commons based licensing regime by creating specializations of a software technology to address plurality of goals and priorities. By ‘forking’ a new branch of development separate from the main project, development diverges into a path in order to relieve tensions related to specialization, which later encounters new tensions. In this study, we first classify forces and patterns within this divergence process. Such tensions may stem from a variety of sources including internal power conflicts, emergence of new environmental niches such as demand for specialized uses of same software, or differences along stability vs. development speed trade-off. We then present an evolutionary model which combines divergence options available to resolve tensions, and how further tensions emerge. In developing this model we attempt to define open software evolution at the level of systems of software, rather than at individual software project level.
Keywords: divergence; forking; software evolution; specialization

Free and Open Source Software Adoption in Emerging Markets: An Empirical Study in the Education Sector - Gangadharan, G.R.; Butler, Martin (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
The adoption of Free and Open Source Software (FOSS) in the education sector in emerging markets holds much promise, but should be accompanied by a well-informed decision to ensure that the potential value is realized. The research conducted provides insight into the pragmatic factors driving the adoption of FOSS in the education environment, as well as those aspects inhibiting adoption. This study indicates an increasing readiness to accept FOSS in the education sector, where the more successful organizations show a readiness to adopt a comprehensive decision model to ensure the installation of appropriate ICT infrastructure, including FOSS, for the future.

Free/Libre Open Source Software: What We Know and What We Do Not Know - Kevin Crowston; Kangning Wei; Howison, James; Andrea Wiggins (ACM Computing Surveys, 2012)
We review the empirical research on Free/Libre Open Source Software (FLOSS) development and assess the state of the literature. Our review is organized around an input-mediator-output-input (IMOI) model. We start with a description of the articles selected for the review. We then discuss findings of this literature categorized into issues pertaining to inputs (e.g., member characteristics, technology use and project characteristics), processes (software development and social processes), emergent states (e.g., trust and task related states) and outputs (e.g. team performance, FLOSS implementation and project evolution). Based on this review, we suggest research questions, including methodological and theoretical issues, to guide future inquiry in this area.

From Open Source Software to Open Source Hardware - Viseur, Robert (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
The open source software principles progressively give rise to new initiatives for culture (free culture), data (open data) or hardware (open hardware). The open hardware is experiencing a significant growth but the business models and legal aspects are not well known. This paper is dedicated to the economics of open hardware. We define the open hardware concept and determine intellectual property tools we can apply to open hardware, with a strong focus on open source licenses and practices. We next conduct some case studies in order to determine which licenses and business models are used by open hardware companies. We show some strong similarities with open source software and propose new opportunities for future works.

Future Smart Metering Runs on Open Source – Challenges and the GuruxAMI Project - Kurunsaari, Mikko (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
More and more devices are coming to Internet and organizations are using more devices to measure things. Challenges include a huge amount of different protocols and a risk of technological lock-in. Because of new innovations and demands new protocols are coming out all the time. Increasing amount of protocols makes it harder to collect data from different data sources and save it to one place. If we want to make tailored reports it is important that we can save all collected data to the one place. This paper presents an overview of how the industrial research project GuruxAMI (Gurux Advanced Metering Infrastructure) tries to solve this problem. An overarching goal of the project is to make an open platform that can be used to collect data from different data sources using different protocols and save collected data to the one place. This will be done by developing Open Source platform that can handle different protocols.

Gender Differences in Early Free and Open Source Software Joining Process - Kuechler, Victor; Gilbertson, Claire; Jensen, Carlos (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
With the growth of free and open source software (FOSS) and the adoption of FOSS solutions in business and everyday life, it is important that projects serve their growingly diverse user base. The sustainability of FOSS projects relies on a constant influx of new contributors. Several large demo- graphic surveys found that FOSS communities are very homogenous, dominated by young men, similar to the bias existing in the rest of the IT workforce. Building on previous research, we examine mailing list subscriptions and posting statistics of female FOSS participants. New participants often experience their first interaction on a FOSS project’s mailing list. We explored six FOSS projects – Buildroot, Busybox, Jaws, Parrot, uClibc, and Yum. We found a declining rate of female participation from the 8.27% of subscribers, to 6.63% of posters, and finally the often reported code contributor rate of 1.5%. We found a disproportionate attrition rate among women along every step of the FOSS joining process.
Keywords: buildroot; busybox; diversity; email; jaws; joining process; mailing lists; parrot; uClibc; Yum

How Can Open Standards Be Effectively Implemented in Open Source? Challenges and the ORIOS Project - Lundell, Björn; AbduraHmanovic, Admir; Andersson, Stefan; Bergström, Erik; Feist, Jonas; Gamalielsson, Jonas; Gustavsson, Tomas; Kahlbom, Roger; Papaxanthis, Konstantin (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Many organisations are currently restricted in their choice of software because of restrictions imposed by existing systems. Challenges include a lack of interoperability and a risk of technological lock-in, which many small companies seek to address by utilising Open Standards and Open Source implementations of such standards when developing and deploying systems. This paper presents an overview of how the industrial research project ORIOS (Open Source software Reference Implementations of Open Standards) seeks to address identified challenges. An overarching goal of the project is to improve understanding within organisations of Open Standards, Open Source Reference Implementations, and the ecosystems around them. This will be done by developing a reference model of necessary and desirable features of an Open Standard, and how Open Standards and their implementations can be utilised by small companies in different usage contexts. An action case study approach will be used as a core strategy for evolving a reference model together with Swedish companies.

How do open source communities blog? - Pagano, Dennis; Maalej, Walid (Empirical Software Engineering, 2012)
We report on an exploratory study, which aims at understanding how software communities use blogs compared to conventional development infrastructures. We analyzed the behavior of 1,100 bloggers in four large open source communities, distinguishing between committing bloggers and other community members. We observed that these communities intensively use blogs with one new entry every 8 h. A blog entry includes 14 times more words than a commit message. When analyzing the content of the blogs, we found that committers and others bloggers write about similar topics. Most popular topics in committers’ blogs represent high-level concepts such as features and domain concepts, while source code related topics are discussed in 15% of their posts. Other community members frequently write about community events and conferences as well as configuration and deployment topics. We found that the blogging peak period is usually after the software is released. Moreover, committers are more likely to blog after corrective engineering than after forward engineering and re-engineering activities. Our findings call for a hypothesis-driven research to (a) further understand the role of social media in dissolving the collaboration boundaries between developers and other stakeholders and (b) integrate social media into development processes and tools.
Keywords: blog; blogs

How the FLOSS Research Community Uses Email Archives - Squire, Megan (International Journal of Open Source Software and Processes, 2012)
Artifacts of the software development process, such as source code or emails between developers, are a frequent object of study in empirical software engineering literature. One of the hallmarks of free, libre, and open source software (FLOSS) projects is that the artifacts of the development process are publicly-accessible and therefore easily collected and studied. Thus, there is a long history in the FLOSS research community of using these artifacts to gain understanding about the phenomenon of open source software, which could then be compared to studies of software engineering more generally. This paper looks specifically at how the FLOSS research community has used email artifacts from free and open source projects. It provides a classification of the relevant literature using a publicly-available online repository of papers about FLOSS development using email. The outcome of this paper is to provide a broad overview for the software engineering and FLOSS research communities of how other researchers have used FLOSS email message artifacts in their work
Keywords: email; email archives; literature; mailing lists; review; Survey

Hybrid Business Models in Software Product Industry: Patterns and Challenges - Deodhar, Swanand J.; Saxena, Kalbhushan C.; Ruohonen, Mikko (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
Operating in software product industry is becoming an increasingly risky proposition. Compressed timeline for product development combined with need to reduce cost has compelled organizations to look at new ways of doing business. One such avenue is combining the erstwhile conflicting practices of open source and closed source software. This industry paper highlights common patterns and challenges encountered in operationalizing such business models. The findings are based on a larger multiple case study research involving six such software products.

The Impact of Formal QA Practices on FLOSS Communities – The Case of Mozilla - Barham, Adina (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
The number of FLOSS projects that include a QA step in the development model is increasing which suggests that a new layer may be emerging in the classic “onion model”. This change might affect the information flow within projects and implicitly their sustainability. Communities, the essential resource of FLOSS projects, have been extensively studied but questions concerning QA remain. This paper takes a step towards answering such questions by analyzing QA mailing lists and issue tracker data for the Mozilla group of projects. Because the Bugzilla data set contains over half a million bugs, data processing and analysis is a considerable challenge for this research. The provisional conclusions are that QA activity may not be increasing steadily over time but is dependent on other factors and that the QA team and other groups of contributors form a highly connected network that doesn’t contain isolates.
Keywords: email; information flow; mailing lists; mozilla; quality assurance; social network analysis; test

Integrating developer-related information across open source repositories - Iqbal, Aftab; Hausenblas, Michael (2012 IEEE 13th International Conference on Information Reuse & Integration (IRI)2012 IEEE 13th International Conference on Information Reuse & Integration (IRI), 2012)
Software developers use various software repositories in order to interact with each other or to solve software related problems. They are required to adopt an identity for each of the software repositories they wanted to use. Quite often developers are also found on different code forges developing open source projects. It is worth mentioning that the information relevant to the developers are distributed on the Web among different data sources each requires an ID and an authentication mechanism. In this paper, we propose to interlink the identities of a developer across different data sources on the Web. Further, we show the benefit of integrating developer-related information from different data sources using some real-world scenarios.

Integrating FLOSS repositories on the Web - Iqbal, Aftab; Cyganiak, Richard; Hausenblas, Michael (DERI Technical Report 2012-12-10, 2012)
This paper provides a novel approach to the problem of integrating data from multiple code forges of FLOSS. We review the current problems in integrating the data from multiple forges and argue that Semantic Web technologies are suitable for representing knowledge contained in code forges. Further, we show the advantage of linking the metadata of projects to other data sources on the Web which will enable querying extra information from the Web. The paper briefly describes how the modeling is achieved and what benefits can be obtained by enabling linking to other relevant data sources already available on the Web.
Keywords: flossmole; google code; sourceforge

Internet Success: A Study of Open Source Software Commons - Schweik, C. M.; English, R. (MIT Press, 2012)
Keywords: flossmole; srda

Licensing Security - Alspaugh, Thomas A.; Walt Scacchi (Proceedings of the 2012 Fifth International Workshop on Requirements Engineering and Law (RELAW), 2012)
There exist legal structures defining the exclusive rights of authors, and means for licensing portions of them to others in exchange for appropriate obligations. We propose an analogous approach for security, in which portions of exclusive security rights owned by system stakeholders may be licensed as needed to others, in exchange for appropriate security obligations. Copyright defines exclusive rights to reproduce, distribute, and produce derivative works, among others. We envision exclusive security rights that might include the right to access a system, the right to run specific programs, and the right to update specific programs or data, among others. Such an approach uses the existing legal structures of licenses and contracts to manage security, as copyright licenses are used to manage copyrights. At present there is no law of “security right” as there is a law of copyright, but with the increasing prevalence and prominence of security attacks and abuses, of which Stuxnet and Flame are merely the best known recent examples, such legislation is not implausible. We discuss kinds of security rights and obligations that might produce fruitful results, and how a license structure and approach might prove more effective than security policies.

A Linguistic Analysis on How Contributors Solve Software Problems in a Distributed Context - Masmoudi, Héla; Boughzala, Imed (IFIP Advances in Information and Communication Technology 378 (OSS 2012), 2012)
There is a little understanding of distributed solving activities in Open Source communities. This study aimed to provide some insights in this way. It was applied to the context of Bugzilla, the bug tracking system of Mozilla community. This study investigated the organizational aspects of this meditated, complex and highly distributed context through a linguistic analysis method. The main finding of this research shows that the organization of distributed problem-solving activities in Bugzilla isn’t based only on the hierarchical distribution of the work between core and periphery participants but on their implication in the interactions. This implication varies according to the status of each one participant in the community. That is why we distinguish their roles, as well as, the established modes to manage such activity.
Keywords: bug report; bugzilla; linguistic; text mining