Project Entity Matching across FLOSS Repositories - Conklin, Megan (OSS2007: Open Source Development, Adoption and Innovation (IFIP 2.13), 2007)
Much of the data about free, libre, and open source (FLOSS) software development comes from studies of code repositories used for managing projects. This paper presents a method for integrating data about open source projects by way of matching projects (entities) and deleting duplicates across multiple code repositories. After a review of the relevant literature, a few of the methods are chosen and applied to the FLOSS domain, including a simple scoring system for confidence in pairwise project matches. Finally, the paper describes limitations of this approach and recommendations for future work.

Promoting the Penguin: Who is Advocating Open Source Software in Commercial Settings? - Oliver Alexy; Joachim Henkel (2007)
Most firms that use or develop software today face the questions of whether and how to engage in open source software. Yet, little is known about the process of OSS adoption and diffusion within corporations. Guided by the theoretical frameworks of Rogers (innovation diffusion) and Davis (Technology Acceptance Model), we develop a model of how job function influences individuals??? proclivity to support their employers??? adoption of OSS and OSS practices. We argue that job function determines which tasks in the software development process are part of an individual???s daily routine, and that different tasks are differentially affected by OSS. Our study is based on interviews with 25 individuals and a large-scale survey distributed to 249 participants in the telecommunications department of a multinational company. The results, although consistent with theoretical considerations, are nevertheless surprising. Distinguishing between developers, software testers, software architects, project managers, and managers, we find greater involvement in OSS activities to be favored most strongly by software testers, followed by software architects and managers. Excepting project managers, developers, despite having the most experience with OSS, are the least favorably disposed to greater corporate engagement in OSS. A corporation interested in adopting OSS and open innovation processes should thus take into account the job function-related incentives of each individual as well as various organizational factors. More generally, we propose that models developed to predict IT adoption behavior be extended to account for the ways in which individual adopters interact with the innovation at hand, which we maintain will be determined largely by their job functions.

Putting a Value on Openness: The Effect of Product Source Code Releases on the Market Value of Firms - Oliver Alexy; Joachim Henkel (2007)
This study examines the effect of releasing the source code of commercial software products as open source software on the market value of firms. Using a sample of 30 software companies in the time span from 1 January 1999 to 30 April 2007, I find that market valuation is influenced by investor sentiment???abnormal returns take a curvilinear shape over time???and the business model firms choose for their OSS efforts???non-existence of an explicit revenue model is punished by the capital market. From my findings, I deduce several implications for IT-related event studies and research on open innovation processes.

Quality Improvement in Volunteer Free and Open Source Software Projects - Martin Michlmayr (2007)
Free and open source software has had a major impact on the computer industry since the late 1990s and has changed the way software is perceived, developed and deployed in many areas. Free and open source software, or FOSS, is typically developed in a collaborative fashion and the majority of contributors are volunteers. Even though this collaborative form of development has produced a significant body of software, the development process is often described as unstructured and unorganized. This dissertation studies the FOSS phenomenon from a quality perspective and investigates where improvements to the development process are possible. In particular, the focus is on release management since this is concerned with the delivery of a high quality product to end-users. This research has identified considerable interest amongst the FOSS community in a novel release management strategy, time based releases. In contrast to traditional development which is feature-driven, time based releases use time rather than features as the criterion for the creation of a new release. Releases are made after a specific interval, and new features that have been completed and sufficiently tested since the last release are included in the new version. This dissertation explores why, and under which circumstances, the time based release strategy is a viable alternative to feature-driven development and discusses factors that influence a successful implementation of this release strategy. It is argued that this release strategy acts as a coordination mechanism in large volunteer projects that are geographically dispersed. The time based release strategy allows a more controlled development and release process in projects which have little control of their contributors and therefore contributes to the quality of the output.

Quality Specification, Testing and Certification of Bespoken, Open Source and Commercial Off-The-Shelf Systems - Hausen, Hans-Ludwig (OSS2007: Open Source Development, Adoption and Innovation (IFIP 2.13), 2007)
The seminar will cover the principles as well as the best practices of software system quality assurance (comprising inspection, verification, validation, black and white box test, measurement and assessment, and the normative quality characteristics) for procedural, object-oriented, aspectoriented and agent-based dependable software. Attendees will exercise proven techniques for goal-directed quality specification, testing, measurement, scaling and assessment for software certification. Assessment of both the software product as well as the software process will be discussed with respect to its relevance for such acceptance assessments. A standardized process model for measurement, assessment and certification of dependable software will be used to make the attendees familiar with this comprehensive assessment procedure and to learn how to embed it into today’s standardized or non-standardized software processes.

The Quest for Quality Tags. - Shilad Sen; Harper, F. Maxwell; Adam LaPitz; John Riedl (Conference on Supporting Group Work, 2007)

Recommenders Everywhere: The WikiLens Community-Maintained Recommender System - Dan Frankowski; Shyong K. Lam; Shilad Sen; Harper, F. Maxwell; Scott Yilek; Michael Cassano; John Riedl (Wikisym 2007, 2007)

Recommending Emergent Teams - Minto, Shawn; Murphy, Gail C. (Fourth International Workshop on Mining Software Repositories (MSR'07:ICSE Workshops 2007), 2007)
To build successful complex software systems, developers must collaborate with each other to solve issues. To facilitate this collaboration, specialized tools, such as chat and screen sharing, are being integrated into development environments. Currently, these tools require a developer to maintain a list of other developers with whom they may wish to communicate and to determine who within this list has expertise for a specific situation. For large, dynamic projects, like several successful open-source projects, these requirements place an unreasonable burden on the developer. In this paper, we show how the structure of a team emerges from how developers change software artifacts. We introduce the Emergent Expertise Locator (EEL) that uses emergent team information to propose experts to a developer within their development environment as the developer works. We found that EEL produces, on average, results with higher precision and higher recall than an existing heuristic for expertise recommendation.
Keywords: bugzilla; developers; eclipse; evolution; expertise; Firefox; teams

Release Management in Free Software Projects: Practices and Problems - Martin Michlmayr; Hunt, Francis; Probert, David (OSS2007: Open Source Development, Adoption and Innovation (IFIP 2.13), 2007)
Release management plays an important role in every software project since it is concerned with the delivery of a high quality product to end-users. This paper explores release practices employed by volunteer free software projects and shows problems that occur. A challenge that has been identified is the difficulty of coordinating a distributed team of volunteers in order to align their work for a release.

Release Pattern Discovery via Partitioning: Methodology and Case Study - Hindle, Abram; Godfrey, Michael W.; Holt, Richard C. (Fourth International Workshop on Mining Software Repositories (MSR'07:ICSE Workshops 2007), 2007)
The development of Open Source systems produces a variety of software artifacts such as source code, version control records, bug reports, and email discussions. Since the development is distributed across different tool environments and developer practices, any analysis of project behavior must be inferred from whatever common artifacts happen to be available. In this paper, we propose an approach to characterizing a project's behavior around the time of major and minor releases; we do this by partitioning the observed activities, such as artifact check-ins, around the dates of major and minor releases, and then look for recognizable patterns. We validate this approach by means of a case study on the MySQL database system; in this case study, we found patterns which suggested MySQL was behaving consistently within itself. These patterns included testing and documenting that took place more before a release than after and that the rate of source code changes dipped around release time.
Keywords: bitkeeper; bt2csv; cvs; evolution; mysql; releases; revision history; scm; softchange; version control

Reusing an open source application — practical experiences with a mobile CRM pilot - Akkanen, Jyrki; Demeter, Hunor; Eppel, Tamás; Ivánfi, Zoltán; Nurminen, Jukka; Stenman, Petri (OSS2007: Open Source Development, Adoption and Innovation (IFIP 2.13), 2007)
We discuss experiences in extending an open source CRM application to develop a new server-based mobile business application. Combining the application code reuse with incremental development process allowed successful development of a pilot application in a tight schedule. In particular, it enabled a quick start for customer-driven development, diminished risks related to the baseline application itself, and provided the flexibility needed in experimental pilot development.

Role Migration and Advancement Processes in OSSD Projects: A Comparative Case Study - Chris Jensen; Walt Scacchi (2007)
Socio-technical processes have come to the forefront of recent analysis of the open source software development (OSSD) world. Interest in making these processes explicit is mounting from industry and the software process community, as well as among those who may become contributors to an OSSD organization. This paper serves to close this gap by providing an analysis of the role migration and project career advancement process, and role-sets within, that we have observed within three large OSSD project organizations: Mozilla.org, Apache.org, and NetBeans.org.

The role of face-to-face meetings in technology-supported self-organizing distributed teams - Kevin Crowston; James Howison; Chengetai Masango; Eseryel, U. Yeliz (Ieee Transactions on Professional Communication, 2007)
We examine the role of face-to-face meetings in the context of technology-supported self-organizing distributed (or virtual teams), specifically Free/Libre Open Source Software (FLOSS) development teams. Based on a qualitative inductive analysis of data from interviews and observations at FLOSS conferences, we identify a variety of settings in which developers meet face-to-face, and we point out the activities performed in these settings and the benefits obtained. Contrary to conventional wisdom about distributed teams, FLOSS developers generally do not meet face-to-face until the project is well under way. An additional benefit offace-to-face meetings is time away from a regular job and speed of interaction for certain kinds of tasks.

The role of trust in OSS communities — Case Linux Kernel community - Antikainen, Maria; Aaltonen, Timo; Väisänen, Jaani (OSS2007: Open Source Development, Adoption and Innovation (IFIP 2.13), 2007)
Open source software development has been the subject of interest among businesses as well as in the academic world. OSS enables many possibilities for companies but also sets new kinds of challenges. Because of the characteristics of the OSS phenomenon we propose that trust in OSS communities plays a key role in facilitating their success. Therefore, the aim of this study is to explore the factors that affect trust in OSS communities. The data is gathered by a survey aimed to Linux Kernel developers. Among other results it may be concluded that the most important factors affecting trust seem to be other developers’ skills, reputation as well as the formal and informal practices.

Seeking Open Infrastructure: Contrasting Open Standards, Open Source and Open Innovation - Joel West (First Monday, 2007)

Self-organization of teams for free/libre open source software development - Kevin Crowston; Li, Qing; Kangning Wei; Eseryel, U. Yeliz; Howison, James (Information and Software Technology Journal, 2007)
This paper provides empirical evidence about how free/libre open source software development teams self-organize their work. Following a case study methodology, we examined developer interaction data from three active and successful FLOSS projects using qualitative research methods, specifically inductive content analysis, to identify the task-assignment mechanisms used by the participants. We found that "self-assignment" was the most common mechanism across three FLOSS projects. This mechanism is consistent with expectations for distributed and largely volunteer teams. We conclude by discussing whether these emergent practices can be usefully transferred to mainstream practice and indicating directions for future research.
Keywords: case study; compiere; coordination; DESIGN; distributed teams; egroupware; email; email archives; forum; free/libre open source software development; gaim; INTERNET; mailing list; metadata; qualitative research methods; self-organizing teams; sourceforge; SYSTEMS; task assignment; WORK

Shared Assumption Concerning Technical Determination in Apache Web Server Developer Community - Juho Lindman (OSS2007: Open Source Development, Adoption and Innovation (IFIP 2.13), 2007)
Our main finding is that OSS community seems to coordinate its activities by relying on technical determination. First, we review previous literature to understand OSS community coordination mechanisms. Then we empirically review OSS Apache Web Server community by using qualitative case study methods. Our data consist of developer list’s email-discussions. Finally, we speculate that coordination rests on community’s members’ shared assumption concerning technical determination.

Simulation of the temporal evolution of OSS projects: application to XMMS and MPLAYER - Antoniades, Ionannis; Kontoyiannis; Ioannis Stamelos; Deligiannis, Ignatios (2nd Workshop on Public Data about Software Development (WoPDaSD 2007), 2007)

Social capital, structural holes and team composition: collaborative networks of the open source software community - Yong Tan; Vijay Mookerjee; Param Vir Singh (International Conference on Information Systems, 2007)
Keywords: NotreDameArchive

Social Comparisons to Motivate Contributions to an Online Community. - F. Harper; X. Li; Y. Chen; J. Konstan (Persuasive Technology, 2007)

Social network structures in open source software development teams - Long, Y.; Siau, K. (Journal of Database Management, 2007)
Drawing on social network theories and previous studies, this research examines the dynamics of social network structures in open source software (OSS) teams. Three projects were selected from SourceForge.net in terms of their similarities as well as their differences. Monthly data were extracted from the bug tracking systems in order to achieve a longitudinal view of the interaction pattern of each project. Social network analysis was used to generate the indices of social structure. The finding suggests that the interaction pattern of OSS projects evolves from a single hub at the beginning to a corel periphery model as the projects move forward.
Keywords: bug tracking; bugs; COMMUNITY; INNOVATION; longitudinal study; MODEL; open source; social; social network analysis; social networks; sourceforge; structure

Spam Filter Based Approach for Finding Fault-Prone Software Modules - Mizuno, Osamu; Ikami, Shiro; Nakaichi, Shuya; Kikuno, Tohru (Fourth International Workshop on Mining Software Repositories (MSR'07:ICSE Workshops 2007), 2007)
Because of the increase of needs for spam e-mail detection, the spam filtering technique has been improved as a convenient and effective technique for text mining. We propose a novel approach to detect fault-prone modules in a way that the source code modules are considered as text files and are applied to the spam filter directly. In order to show the applicability of our approach, we conducted experimental applications using source code repositories of Java based open source developments. The result of experiments shows that our approach can classify more than 75% of software modules correctly.
Keywords: argouml; bug reports; classification; eclipse; java; modules; scm; spam; text mining

Sprint-driven development: working, learning and the process of enculturation in the PyPy community - Sigfridsson, Anders; Avram, Gabriela; Sheehan, Anne; Sullivan, Daniel (OSS2007: Open Source Development, Adoption and Innovation (IFIP 2.13), 2007)
In this paper we examine sprint-driven software development as it occurs in a specific Open Source community, PyPy. Applying a situated learning perspective, we report the findings from a study focused on the activities leading up to, taking place during, and following after sprints. The study included analyses of sprint reports, email archives and other documents available on the community website, as well as a one-week period of direct observation of a specific sprint. The objective of the study was to elaborate on how the practices of sprint-driven development in the PyPy community facilitate learning, the dissemination of knowledge among its members and the expansion of the Open Source community. This paper aims to assess how sprint-driven development can facilitate situated learning in distributed software development by describing the practices applied in PyPy.

Stakeholder value, usage, needs and obligations from differnet types of F/LOSS licenses - Skidmore, Darren (OSS2007: Open Source Development, Adoption and Innovation (IFIP 2.13), 2007)
This paper discusses different types of Stakeholders of F/LOSS, their needs, the value, usage, and obligations that stakeholders have for different types of F/LOSS licenses. Stakeholders include Developers: Individuals, Projects, Embedded Systems. Vendors: Dominant, Niche, F/LOSS. Packagers. End Users. Organisations: Disseminators, Internally, Externally Used.

Study of Available Tools - Antoniades, Ionannis; Samoladas, Ioannis; Sowe, Sulayman K.; Gregorio Robles; Koch, Stefan; Fraczek, Ksenia; Hadzisalihovic, Anis (FLOSSmetrics, 2007)

Studying Production Phase SourceForge Projects: An Exploratory Analysis Using cvs2mysql and SFRA - Delorey, Daniel P.; Knutson, Charles D.; MacLean, Alexander C. (2nd Workshop on Public Data about Software Development (WoPDaSD 2007), 2007)
A wealth of data can be extracted from the natural by-products of software development processes and used in empirical studies of software engineering. However, the size and accuracy of such studies depend in large part on the availability of tools that facilitate the collection of data from individual projects and the combination of data from multiple projects. To demonstrate this point, we present our experience gathering and analyzing data from nearly 10,000 open source projects hosted on SourceForge. We describe the tools we developed to collect the data and the ways in which these tools and data may be used by other researchers. We also provide examples of statistics that we have calculated from these data to describe interesting author- and project-level behaviors of the SourceForge community.
Keywords: Data Collection; forge; repositories; sourceforge

Studying Versioning Information to Understand Inheritance Hierarchy Changes - Rysselberghe, Filip Van; Demeyer, Serge (Fourth International Workshop on Mining Software Repositories (MSR'07:ICSE Workshops 2007), 2007)
With the widespread adoption of object-oriented programming, changing the inheritance hierarchy became an inherent part of today's software maintenance activities. Unfortunately, little is known about the "state-of-the-practice" with respect to changing an application's inheritance hierarchy, and consequently we do not know how the change process can be improved. In this paper, we report on a study of the hierarchy changes stored in a versioning system to explore the answers to three research questions: (1) why are hierarchy changes made? (2) what kind of hierarchy changes are made? (3) what is the impact of these changes? Based on the results of this study, we formulate 7 hypotheses which should be investigated further to make conclusive interpretations on how hierarchy changes fit in the actual change process.
Keywords: argouml; change management; inheritance; jedit

Surveying Industrial Roles in Open Source Software Development - Hauge, Øyvind; Sørensen, Carl-Fredrik; Røsdal, Andreas (OSS2007: Open Source Development, Adoption and Innovation (IFIP 2.13), 2007)
Industry uses Open Source Software (OSS) to a greater and greater extent. We have defined four industrial OSS roles; OSS provider, OSS integrator, OSS participant and Inner Source Software (ISS) participant. Based on these four roles we have performed a survey in the ITEA COSI project. We provide initial answers to what motivates companies to undertake these roles, what are the advantages and challenges of undertaking them, and which development practices they use while undertaking these roles.

"A system that works for me" - an anthropological analysis of computer hackers' shared use and development of the Ubuntu system - Andreas Lloyd (2007)
Based on 6 months of anthropological fieldwork both on-line and in-person among the developers working to develop and maintain the Ubuntu Linux system, this thesis examines the individual and collaborative day-to-day practices of these developers as they relate to the computer operating system that is the result of their labour. Despite being spread across the industrialized world, these ""hackers"" socialise, share their knowledge, and come to depend on each other in their work across the Internet, as well as in their in-person meetings at conferences and summits. I argue that these shared and negotiated on-line and in-person practices constitute a community of practice (Wenger 1998) rooted in a more than 40-year old "oral"computing tradition based on the Unix operating system. Taking the Ubuntu system as my point of departure, I examine the network of practices, processes and actors in which it has been constructed, and through a strategically selected constellation of theories drawn from anthropology, philosophy, and new media studies, I seek to describe and analyze the three central dimensions of a community of practice. I conclude by suggesting that it is the possibility to adopt, learn, configure, and even build the system according to their own needs, which opens the meritocratic community of practice for new contributors to scale the steep curve of learning necessary to enter and learn among them. In this way, the Ubuntu hackers come to share more than just the same system, they come to share a common history, and, to a certain extent, a shared identity through their practice.

Talk Amongst Yourselves: Inviting Users to Participate in Online Conversations. - F. Harper; D. Frankowski; Drenner, S.; Y. Ren; S. Kiesler; Terveen, L.; Kraut, R.; Riedl, J. (International Conference on Intelligent User Interfaces, 2007)

A test of Lazear's theory of entrepreneurship in the Open Source Software virtual community - Paola Giuri; Francesco Rullani; Salvatore Torrisi (2007)
This paper studies the emergence of entrepreneurs and their skill profile in the open source software community. We test the hypothesis that entrepreneurs, carrying out complex, multi-task activities, have more balanced skill sets compared with individuals who are less involved in project management activities. Our empirical analysis employs the SourceForge dataset containing information on 77,039 individuals working in 54,229 OSS projects. We estimate logit and ordered logit models to explore the likelihood that an individual is a project founder or manager. Our main regressors include individual attributes like skill level and diversity, and project-level controls. Results support our hypothesis.

Toward a New Industrial Organization? OSS in Economic and Managerial Perspective - Dalle, Jean; Cristina Rossi; Francesco Rullani (OSS2007: Open Source Development, Adoption and Innovation (IFIP 2.13), 2007)
At present, an more and more users are running Open Source software (OSS) on their systems. Major companies, like IBM, Oracle, or Sun Microsystems, have now started to make significant investments in developing open communities and creating a portfolio of systems incorporating OSS applications into their design. Meanwhile, an increasing number of firms are entering the market by offering OSS-based solutions to their customers, often supplying a mix of proprietary and open solutions through hybrid business models. In this context, economists and management scientists are now moving beyond the state of puzzlement that has driven much of the initial attention towards OSS. Located in the context of OSS2007 in order to foster close and fruitful interactions with scholars from various other disciplines, this workshop aims at contributing to the current evolutions of the economic and managerial research agendas about OSS, and thus to provide, first, an assessment of where we — economics and management scholars - are about OSS, and, second, an analysis of the renewed directions in which we should consider inquiring further in the near future, focusing notably on business, production, diffusion and innovation models.

Towards a Theoretical Model for Software Growth - Herraiz, Israel; Jesus M. Gonzalez-Barahona; Gregorio Robles (Fourth International Workshop on Mining Software Repositories (MSR'07:ICSE Workshops 2007), 2007)
Software growth (and more broadly, software evolution) is usually considered in terms of size or complexity of source code. However in different studies, usually different metrics are used, which make it difficult to compare approaches and results. In addition, not all metrics are equally easy to calculate for a given source code, which leads to the question of which one is the easiest to calculate without losing too much information. To address both issues, in this paper present a comprehensive study, based on the analysis of about 700,000 C source code files, calculating several size and complexity metrics for all of them. For this sample, we have found double Pareto statistical distributions for all metrics considered, and a high correlation between any two of them. This would imply that any model addressing software growth should produce this Pareto distributions, and that analysis based on any of the considered metrics should show a similar pattern, provided the sample of files considered is large enough.
Keywords: C; complexity; evolution; freebsd; growth; halstead; lines of code; loc; mccabe; metrics; scm; size; sloc; sloccount; source code

Towards an Open Ontology for Emergency Response - Paola Di Maio (2007)
Emergency Response and Relief Coordination Efforts are evolving to leverage the efficiencies offered by the internet in the area of real time communication among agents and stakeholders. There is widespread consensus both in the technical and ER community that to improve efficiency of response, information must be shared and web based protocols must be used [22]. In addition to known technical and non-technical obstacles that inhibit the effective and seamless coordination of operations, we identify issues that challenge the development of functional information and communication models. Recent studies in ontology engineering, and evidence from direct observations of open-source work groups in this field, point to the need for an easy to use 'open' conceptual and semantic framework, defined here broadly as ???Open Ontology??? (OOnt), and a corresponding design and implementation methodology that can be referenced unambiguously and universally by developers and users of information systems designed to support ER operations.

Towards an understanding of FLOSS: Infrastructures, Materiality and the Digital Business Ecosystem - Mary Darking; Edgar A Whitley (Science Studies, 2007)
In this paper we present empirical work detailing the engagement practices of a large FLOSS project, the Digital Business Ecosystem (DBE). In common with many other FLOSS projects, the DBE project focused on the development of infrastructural software components. Infrastructures and FLOSS software exhibit multiplicity: as objects they both change and stay the same. Whilst the implications of multiplicity with respect to infrastructure have been well-documented, with respect to FLOSS, they remain under-explored. Through examining how the DBE engaged new participants we were able to explore the nature of the FLOSS software object by asking the implied question: engagement with what? We draw on recent analysis by Law and Singleton to show how the innovative yet non-existent potentiality of the DBE was as significant to engagement as its steadily growing codebase. We argue that acknowledging the materiality and immateriality of the FLOSS software object has important consequences for management of, and engagement with, FLOSS projects.
Keywords: engagement; FLOSS; infrastructures; INNOVATION; materiality

On Understanding How to Introduce an Innovation to an Open Source Project - Oezbek, Christopher; Prechelt, Lutz (First International Workshop on Emerging Trends in FLOSS Research and Development (FLOSS'07: ICSE Workshops 2007)First International Workshop on Emerging Trends in FLOSS Research and Development (FLOSS'07: ICSE Workshops 2007), 2007)
We propose to research the introduction of Software Engineering inventions into Open Source projects (1) to help researchers with creating opportunities for evaluating their tools, methods and process designs in real-life settings, and (2) to help Open Source projects with improving their processes based on state-of-the-art knowledge. Such research will go beyond diffusion and dissemination of inventions to active introduction, and thus increase the chances of adoption. We will discuss the research approach, our preliminary insights, limitations of the approach, and why researchers interested in evaluating their own inventions should be interested in this research.

Understanding the Development of Free E-Commerce/E-Business Software: A Resource-Based View - Walt Scacchi (Emerging Free and Open Source Software Practices, 2007)

Understanding the KDE Social Structure through Mining of Email Archive - Studer, Matthias; Müller, Benoît; Ritschard, Gilbert (2nd Workshop on Public Data about Software Development (WoPDaSD 2007), 2007)
In order to achieve a better understanding of FLOSS social structure, we need a definition of social position. From a theoretical perspective, we propose to think the participation as a trajectory. Empirically, we use optimal matching to build a typology of participation trajectories based on KDE email archives. We show how these trajectories structure the community as a whole by combining these results with a social network analysis.
Keywords: bug tracking system; bugzilla; commit; email; email archive; kde; mailing list; participation; revision control; social network analysis

The use of open source GIS software and its impact on organizations - Mahmoud Refaat Nasr (2007)
This thesis explores the reasons behind the poor level of adoption of open source web GIS software, and whether it is due to poor awareness about open source concepts or due to technical deficiencies in the open source tools. The research was done in 2 major phases; the first phase involved conducting surveys to measure the awareness and attitudes towards open source. The surveys examined three categories of people involved in the IT industry, namely: decision makers, software developers, and end users. The measurement of awareness was done by developing an Awareness Indicator and a Sentiment Indicator for each category. These indicators were developed by the author during the course of the study in order to provide a measurable and descriptive indication of the results. The second phase involved performing a comparative analysis between MapServer a leading open source web GIS tool, and three of the leading proprietary web GIS software, namely: ESRI???s ArcIMS, Intergraph???s GeoMedia WebMap, and MapInfo???s MapXtreme. The results of the research provide an insight on how different categories of people view open source, and demonstrate that lack of awareness about open source concepts and its competencies may be a major reason behind the poor adoption of open source solutions. The results of the comparative analysis also demonstrate that MapServer is technically equivalent to its commercial counter parts.

The Use of Open Source Software in Enterprise Distributed Computing Environments - Krivoruchko, Jacob (OSS2007: Open Source Development, Adoption and Innovation (IFIP 2.13), 2007)
Firms increasingly rely on open source software for solving business problems and building mission-critical IT solutions. However, there are numerous issues associated with OSS, including its influence on the total cost of ownership (TCO) and supportability and upgradeability risks. While savings from obtaining a free copy of the software can be significant, software accounts for an average of 10% of TCO, while the majority of the costs are associated with project staffing. OSS requires significant investment into staffing because it needs to be carefully selected, customized, and installed. In addition, global communities may gather and dissolve at their will, so guarantees of support, revision, and bug fixes are minimal. Yet companies can gain competitive advantage through an ability to customize software to address specific business issues and exercising control over development, revision schedules, and modifications. OSS is not a panacea from the rising software costs. Instead, it is a serious initiative that has benefits, disadvantages, and risks associated with it.

Using FLOSSmole Data in Determining Business Readiness Ratings - Wasserman, Anthony; Ashutosh Das (2nd Workshop on Public Data about Software Development (WopDaSD 2007), 2007)
This paper is a preliminary report on using FLOSSmole data retrieved from open source repositories (forges) to calculate Business Readiness Rating scores.
Keywords: brr; business readiness rating; flossmole

Using Repository of Repositories (RoRs) to Study the Growth of F/OSS Projects: A Meta-Analysis Research Approach - Sowe, Sulayman; Lefteris Angelis; Stamelos, I.; Y. Manolopoulos (OSS2007: Open Source Development, Adoption and Innovation (IFIP 2.13), 2007)
Free/Open Source Software (F/OSS) repositories contain valuable data and their usefulness in studying software development and community activities continues to attract a lot of research attention. A trend in F/OSS studies is the use of metadata stored in a repository of repositories or RoRs. This paper utilizes data obtained from such RoRs -FLOSSmole- to study the types of projects being developed by the F/OSS community. We downloaded projects by topics data in five areas (Database, Internet, Software Development, Communications, and Games/Entertainment) from Flossmole’s raw and summary data of the sourceforge repository. Time series analysis show the numbers of projects in the five topics are growing linearly. Further analysis supports our hypothesis that F/OSS development is moving “up the stack” from developer tools and infrastructure support to end-user applications such as Databases. The findings have implications for the interpretation of the F/OSS landscape, the utilization and adoption of open source databases, and problems researchers might face in obtaining and using data from RoRs.

Using Software Distributions to Understand the Relationship among Free and Open Source Software Projects - Daniel M. German (Fourth International Workshop on Mining Software Repositories (MSR'07:ICSE Workshops 2007), 2007)
Success in the open source software world has been measured in terms of metrics such as number of downloads, number of commits, number of lines of code, number of participants, etc. These metrics tend to discriminate towards applications that are small and tend to evolve slowly. A problem is, however, how to identify applications in these latter categories that are important. Software distributions specify the dependencies needed to build and to run a given software application. We use this information to create a dependency graph of the applications contained in such a distribution. We explore the characteristics of this graph, and use it to define some metrics to quantify the dependencies (and dependents) of a given software application. We demonstrate that some applications that are invisible to the final user (such as libraries) are widely used by end-user applications. This graph can be used as a proxy to measure success of small, slowly evolving free and open source software.
Keywords: dependencies; evolution; fink; metrics

Using Software Repositories to Investigate Socio-technical Congruence in Development Projects - Valetto, Giuseppe; Helander, Mary; Ehrlich, Kate; Chulani, Sunita; Wegman, Mark; Williams, Clay (Fourth International Workshop on Mining Software Repositories (MSR'07:ICSE Workshops 2007), 2007)
We propose a quantitative measure of socio-technical congruence as an indicator of the performance of an organization in carrying out a software development project. We show how the information necessary to implement that measure can be mined from commonly used software repositories, and we describe how socio-technical congruence can be computed based on that information.
Keywords: developers; graph; scm; social networks; source code

Value Capture and Value Networks in Open Source Vendor Strategies - Joel West (40th Annual Hawaii International Conference on System Sciences (HICSS'07), 2007)

Visual Data Mining in Software Archives to Detect How Developers Work Together - Weissgerber, Peter; Pohl, Mathias; Burch, Michael (Fourth International Workshop on Mining Software RepositoriesFourth International Workshop on Mining Software Repositories (MSR'07:ICSE Workshops 2007), 2007)
Analyzing the check-in information of open source software projects which use a version control system such as CVS or SUBVERSION can yield interesting and important insights into the programming behavior of developers. As in every major project tasks are assigned to many developers, the development must be coordinated between these programmers. This paper describes three visualization techniques that help to examine how programmers work together, e.g. if they work as a team or if they develop their part of the software separate from each other. Furthermore, phases of stagnation in the lifetime of a project can be uncovered and thus, possible problems are revealed. To demonstrate the usefulness of these visualization techniques we performed case studies on two open source projects. In these studies interesting patterns of developers? behavior, e.g. the specialization on a certain module can be observed. Moreover, modules that have been changed by many developers can be identified as well as such ones that have been altered by only one programmer.
Keywords: change; coordination; cvs; developers; junit; modules; scm; source code; svn; teams; tomcat; visualization

Voluntary Engagement in an Open Web-based Encyclopedia: Wikipedians, and Why They Do It - Joachim Schroer; Guido Hertel (2007)
The online encyclopedia Wikipedia can be considered as a highly successful Open Content project, written and maintained completely by volunteers. Little is known, however, about the motives and interests of these volunteers. Results from an online survey among 106 contributors to the German Wikipedia project are presented. As potential predictors of contributors??? engagement and satisfaction, both motives derived from social sciences (e.g., costs-benefits, valence of the Wikipedia goals, identification with Wikipedia, etc.) as well as perceived task characteristics (e.g., task significance, autonomy, skill variety, etc.) were measured. The results reveal that satisfaction ratings of contributors are determined by perceived benefits, identification with the Wikipedia community, and task characteristics. Contributors??? engagement (e.g., hours per week) was particularly determined by their tolerance for opportunity costs and the experienced characteristics of their tasks, the latter effect being partially mediated by intrinsic motivation. Most relevant task characteristics both for contributors??? engagement and satisfaction were autonomy, task significance, and skill variety. Additional motives reported by Wikipedia contributors suggest the importance of generativity.

Web Mash-ups and Patchwork Prototyping: User-driven technological innovation with Web 2.0 and Open Source Software - Floyd, I.R.; Jones, M.C.; Rathi, D.; Twidale, M.B (2007 40th Annual Hawaii International Conference on System Sciences (HICSS'07)2007 40th Annual Hawaii International Conference on System Sciences (HICSS'07), 2007)
The recent emergence of web mash-ups and open source software is driving the development of new practices in software and systems development. In this paper we explore novel practices of user-driven innovation through an examination of several case studies which illustrate how users and developers are exploiting the proliferation of open APIs and open source systems. Developers can rapidly create proofs of concept that are robust enough for actual use by combining preexisting software components. The underlying programming processes involved make use of tried-and-true software development techniques, and may not appear innovative at first. However, the application of these practices and techniques to problem solving by non-programmers shows a high degree of creative innovation, giving rise to new ways of thinking about technology design and production.

What Can OSS Mailing Lists Tell Us? A Preliminary Psychometric Text Analysis of the Apache Developer Mailing List - Peter C. Rigby; Hassan, Ahmed E. (Fourth International Workshop on Mining Software Repositories (MSR'07:ICSE Workshops 2007), 2007)
Developer mailing lists are a rich source of information about Open Source Software (OSS) development. The unstructured nature of email makes extracting information difficult. We use a psychometrically-based linguistic analysis tool, the LIWC, to examine the Apache httpd server developer mailing list. We conduct three preliminary experiments to assess the appropriateness of this tool for information extraction from mailing lists. First, using LIWC dimensions that are correlated with the big five personality traits, we assess the personality of four top developers against a baseline for the entire mailing list. The two developers that were responsible for the major Apache releases had similar personalities. Their personalities were different from the baseline and the other developers. Second, the first and last 50 emails for two top developers who have left the project are examined. The analysis shows promise in understanding why developers join and leave a project. Third, we examine word usage on the mailing list for two major Apache releases. The differences may reflect the relative success of each release.
Keywords: apache; developers; email; joining; liwc; mailing lists; personality

What motivates Wikipedians: motivations for Wikipedia content contribution - Oded Nov (2007)
Contributors??? motivations are critical for sustaining Wikipedia and other collaborative user-generated content outlets. Such outlets are based on contributions by people who volunteer their time and talent for the creation of content in return for no monetary reward. Therefore, in order to understand what underlies user-generated content contribution, we would need to find out what motivates volunteer content contributors. The results of a survey of 151 Wikipedia contributors indicate that the top motivations for contribution are Fun and Ideology. As expected, it was found that the levels of each of the motivations Fun, Values, Understanding, Enhancement, Protective, and Career were positively correlated with contribution level. Somewhat unexpectedly, contribution level was not correlated significantly with the Ideology and Social motivations.

Working with Open Source Development Data: Considerations triggered by a study of bug scenarios - den Besten, Matthijs; Masmoudi, Héla; Jean-Michel Dalle (2nd Workshop on Public Data about Software Development (WoPDaSD 2007), 2007)
The retrieval and preparation of public data on software development calls for more than just technical skills. In addition, care and judgement are needed to avoid disproportionate costs to the providers of data or unnecessary embarrassment to the participants tracked in the data. Taking the extraction of bug scenarios as a use case, we illustrate these concerns and discuss how they could be translated into social requirements that would help to make retrieval and preparation a sustainable exercise. In particular, we call for more efforts to establish institutional repositories of public data on software development and, besides, we suggest that reviewers could play a role in making sure that empirical research is performed in a way that does not bring the long-term relationship between software developers and researchers in jeopardy.
Keywords: bug reports; bug scenarios; Data Collection

An absorptive capacity perspective of open source software development group performance - Sherae Daniel; Ritu Agarwal; Katherine Stewart (International Conference on Information Systems, 2006)
Keywords: NotreDameArchive

Adopting Open Source for Mission-Critical Applications: A Case Study on Single Sign-On - Ardagna, Claudio; Damiani, Ernesto; Frati, Fulvio; Reale, Salvatore (OSS2006: Open Source Systems (IFIP 2.13), 2006)
In this paper, we describe a specific selection process for security-related open source code, based on a methodology aimed at evaluating open source security frameworks in general and Single-Sign-On (SSO) systems in particular. Our evaluation criteria for open source security-related software include the community’s timeliness of reaction against newly discovered vulnerabilities or incidents.

Analyzing OSS developers' working time using mailing lists archives - Tsunoda, Masateru; Monden, Akito; Kakimoto, Takeshi; Kamei, Yasutaka; Matsumoto, Ken-ichi (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
Our mining question is “when OSS developers work?” OSS developers' working time may be a good indicator to understand the development style of a project. (For example, if many developers work in office hour, these might be daily works in a company.)
Keywords: developers; email; email archives; mailing lists; mining challenge; msr challenge; overtime work; postgresql; workload

Applying Social Network Analysis Techniques to Community-Driven Libre Software Projects - López-Fernández, L.; Gregorio Robles; Jesus M. Gonzalez-Barahona; Herraiz, I. (International Journal of Information Technology and Web Engineering, 2006)
Source code management repositories of large, long-lived libre (free, open source) software projects can be a source of valuable data about the organizational structure, evolution, and knowledge exchange in the corresponding development communities. Unfortunately, the sheer volume of the available information renders it almost unusable without applying methodologies which highlight the relevant information for a given aspect of the project. Such methodology is proposed in this article, based on well known concepts from the social networks analysis field, which can be used to study the relationships among developers and how they collaborate in different parts of a project. It is also applied to data mined from some well known projects (Apache, GNOME, and KDE), focusing on the characterization of their collaboration network architecture. These cases help to understand the potentials of the methodology and how it is applied, but also shows some relevant results which open new paths in the understanding of the informal organization of libre software development communities.
Keywords: apache; conway's law; cvs; gnome; kde; scm; social network analysis; source code

Applying the evolution radar to PostgreSQL - D'Ambros, Marco; Lanza, Michele (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
Keywords: cvs; documentation; evolution; evolution radar; logical coupling; makefile; mining challenge; msr challenge; postgresql; re-engineering; refactoring; release history; rhdb; source code; version control; visualization

Are refactorings less error-prone than other changes? - Weißgerber, Peter; Diehl, Stephan (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
Refactorings are program transformations which should preserve the program behavior. Consequently, we expect that during phases when there are mostly refactorings in the change history of a system, only few new bugs are introduced. For our case study we analyzed the version histories of several open source systems and reconstructed the refactorings performed. Furthermore, we obtained bug reports from various sources depending on the system. Based on this data we identify phases when the above hypothesis holds and those when it doesn't.
Keywords: argouml; bug reports; bugs; change history; jedit; junit; re-engineering; refactoring; reverse engineering; software evolution; version control

Assessing the health of open source communities - Kevin Crowston; James Howison (Computer, 2006)

Because I Carry My Cell Phone Anyway: Functional Location-Based Reminder Applications - Ludford, P.; D. Frankowski; Reily, K.; Wilms, K.; Terveen, L. (ACM SIGCHI Conference on Human Factors in Computing Systems, 2006)

Beyond Low-Hanging Fruit: Seeking the Next Generation in FLOSS Data Mining - Conklin, Megan (OSS2006: Open Source Systems (IFIP 2.13), 2006)
This paper will discuss the motivations and methods for collecting quantitative data about free, libre and open source (FLOSS) software projects. The paper also describes the current state of the art in collecting this data, and some of the problems with this process. Finally, the paper outlines the challenges data miners should look forward to when trying to improve the usefulness of their quantitative data streams.

Bringing Open Source Software to the Desktop : An In-Depth Study of the Implementation and use of Star Office - PJ Wall; Seamas Kelly (2006)
Open Source software is coming to the attention of individuals, organisations, and governments worldwide, and is increasingly being adopted by firms for specific business purposes. However, the uptake of end-user desktop OSS applications to date has been modest, and Microsoft products remain the de-facto standard on the corporate desktop. This brings into sharp focus one of the most challenging questions faced by the Open Source community today ... namely, if organisations value low acquisition costs, low total cost of ownership of software, potentially plentiful support, free access to source code, and the wish to avoid proprietary software vendor lock-in, why have more organisations not adopted OSS? This paper contributes to the existing research by reporting on an in-depth, interpretive, processual study of an attempt by a large Irish Trade Union to replace Microsoft Office with an Open Source alternative, StarOffice.

Call for Quality: Open Source Software Quality Observation - de Groot, Adriaan; Kügler, Sebastian; Adams, Paul; Gousios, Giorgos (OSS2006: Open Source Systems (IFIP 2.13), 2006)
This paper describes how a Software Quality Observatory works to evaluate and quantify the quality of an Open Source project. Such a quality measurement can be used by organizations intending to deploy an Open Source solution to pick one of the available projects for use. We offer a case description of how the Software Quality Observatory will be applied to the KDE project to document and evaluate its quality practices for outsiders.
Keywords: kde; quality

A case study of a corporate open source development model - Gurbani, Vijay K.; Garvert, Anita; Herbsleb, James D. (Proceedings of the 28th international conference on Software engineering, 2006)
Open source practices and tools have proven to be highly effective for overcoming the many problems of geographically distributed software development. We know relatively little, however, about the range of settings in which they work. In particular, can corporations use the open source development model effectively for software projects inside the corporate domain? Or are these tools and practices incompatible with development environments, management practices, and market-driven schedule and feature decisions typical of a commercial software house? We present a case study of open source software development methodology adopted by a significant commercial software project in the telecommunications domain. We extract a number of lessons learned from the experience, and identify open research questions.
Keywords: architecture; case study; open source; session initiation protocol; software development; vkg

Challenges of open innovation: the paradox of firm investment in open-source software - Joel West; Gallagher, Scott (R&D Management, 2006)
Open innovation is a powerful framework encompassing the generation, capture, and employment of intellectual property at the firm level. We identify three fundamental challenges for firms in applying the concept of open innovation: finding creative ways to exploit internal innovation, incorporating external innovation into internal development, and motivating outsiders to supply an ongoing stream of external innovations. This latter challenge involves a paradox, why would firms spend money on R&D efforts if the results of these efforts are available to rival firms? To explore these challenges, we examine the activity of firms in open-source software to support their innovation strategies. Firms involved in open-source software often make investments that will be shared with real and potential rivals. We identify four strategies firms employ

Co-change visualization applied to PostgreSQL and ArgoUML: (MSR challenge report) - Beyer, Dirk (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
Co-change visualization is a method to recover the subsystem structure of a software system from the version history, based on common changes and visual clustering. This paper presents the results of applying the tool CCVisu which implements co-change visualization, to the two open-source software systems PostgreSQL and ArgoUML The input of the method is the co-change graph, which can be easily extracted by CCVisu from a Cvs version repository. The output is a graph layout that places software artifacts that were often commonly changed at close positions, and artifacts that were rarely co-changed at distant positions. This property of the layout is due to the clustering property of the underlying energy model,which evaluates the quality of a produced layout. The layout can be displayed on the screen, or saved to a file in SVG or VRML format.
Keywords: argouml; ccvisu; cvs; force-directed graph layout; graph; mining challenge; msr challenge; postgresql; software clustering; software structure analysis; software visualization; version control; visualization

Collaborative Maintenance in Large Open-Source Projects - den Besten, Matthijs; Jean-Michel Dalle; Galia, Fabrice (OSS2006: Open Source Systems (IFIP 2.13), 2006)
The paper investigates collaborative work among maintainers of open source software by analyzing the logs of a set of 10 large projects. We inquire whether teamwork can be influenced by several characteristics of code. Preliminary results suggest that collaboration among maintainers in most large open-source projects seems to be positively influenced by file vintage and by Halstead volume of files, and negatively by McCabe complexity and size measured in SLOCs. These results could be consistent with an increased attractivity of files created early in the history of a project, and with maintainers being less attracted by more verbose code and by more complex code, although in this last case it might also reflect the fact that more complex files would be de facto more exclusive in terms of maintenance.
Keywords: apache; COLLABORATION; complexity; cvs; gaim; gcc; ghostscript; halstead; lines of code; loc; mccabe; mozilla; netbsd; openssh; postgresql; python; sloc

Commons Identity: A Conceptual Model for Designing Brand Identity in Free and Open Source Software Projects - Nicolas Schudel (2006)
Purpose: Open Source is a popular term to describe a development and production method based on the free sharing of information. The computer software industry has embraced Open Source practices increasingly since the nineties. Participation in Free and Open Source Software projects is commonly voluntary and there is a need for specialized knowledge surrounding the production of software. This report focuses on the topic area of designing brand identity. Objective: To create a conceptual model for designing brand identity in Free and Open Source Software projects based on Wheeler???s Brand Identity Process of 2006. Design: Participatory action research with three cycles and five interviews conducted online. Participants: Three Free and Open Source Software projects named Sociopath, OpenEats, and Jajuk. Five industry professionals with expertise in branding and Open Source development. Results: Wheeler???s brand identity process is modified towards the Open Source method and incorporates community votes and commons-based peer-review. Outcomes specific to Free and Open Source Software projects are included as exemplary brand identity assets. Furthermore, a preparation phase is added showing the entry into the project???s community. Conclusions: The created model is a practical tool for designing brand identity in Free and Open Source Software projects. Further applications of the model are needed for its evaluation.

Communication Networks in an Open Source Software Project - Roberts, Jeffrey; Il-Horn Hann; Sandra Slaughter (OSS2006: Open Source Systems (IFIP 2.13), 2006)
This study explores the nature of the social network and the patterns of communication that exist in an open source software development project, the Apache HTTP (WEB) server project. Our analysis of archival data on email communications between developers in the Apache HTTP server project suggests an interesting pattern of communication. We find that the core developers self-organize into three sub-groups that communicate intensely in completing the project. Our analysis also reveals that a few prominent developers who are centrally located in the network are driving communications within the project. We identify the implications of our findings and suggest areas for further research.
Keywords: apache; core; developers; email; email archive; mailing list; participation; social network analysis

Comparing macro development for personal productivity tools: an experience in validating accessibility of Talking Books - Dodero, Gabriella; Lupi, Katia; Piffero, Erika (OSS2006: Open Source Systems (IFIP 2.13), 2006)
We describe an experience in developing macros for both Power Point and Impress, to be used in accessibility validation for educational multimedia (Talking Books) designed for visually impaired people. Minor disadvantages in the use of Impress are outlined, which however do not constitute a serious obstacle to adoption of Open Source tools for our purposes.

Comparison Between SLOCs and Number of Files As Size Metrics for Software Evolution Analysis - Herraiz, Israel; Gregorio Robles; Gonzalez-Barahon, Jes us M. (Proceedings of the Conference on Software Maintenance and Reengineering, 2006)
Keywords: empirical studies; libre software; metrics; software evolution

Conceptual Modelling as a New Entry in the Bazaar: The Open Model Approach - Koch, Stefan; Strecker, Stefan; Frank, Ulrich (OSS2006: Open Source Systems (IFIP 2.13), 2006)
The present contribution proposes to transfer the main principles of open source software development to a new context: conceptual modelling; an activity closely related to software development. The goal of the proposed “open model” approach is to collaboratively develop reference models for everyone to copy, use and refine in a public process. We briefly introduce conceptual modelling and reference models, discuss the cornerstones of an open modelling process, and propose a procedure for initiating, growing and sustaining an open model project. The paper concludes with a discussion of potential benefits and pitfalls.

Contributor Turnover in Libre Software Projects - Gregorio Robles; Gonzalez-Barahona, Jesus (OSS2006: Open Source Systems (IFIP 2.13), 2006)
A common problem that management faces in software companies is the high instability of their staff. In libre (free, open source) software projects, the permanence of developers is also an open issue, with the potential of causing problems amplified by the self-organizing nature that most of them exhibit. Hence, human resources in libre software projects are even more difficult to manage: developers are in most cases not bound by a contract and, in addition, there is not a real management structure concerned about this problem. This raises some interesting questions with respect to the composition of development teams in libre software projects, and how they evolve over time. There are projects lead by their original founders (some sort of “code gods”), while others are driven by several different developer groups over time (i.e. the project “regenerates” itself). In this paper, we propose a quantitative methodology, based on the analysis of the activity in the source code management repositories, to study how these processes (developers leaving, developers joining) affect libre software projects. The basis of it is the analysis of the composition of the core group, the group of developers most active in a project, for several time lapses. We will apply this methodology to several large, well-known libre software projects, and show how it can be used to characterize them. In addition, we will discuss the lessons that can be learned, and the validity of our proposal.
Keywords: apache; committers; core; cvs; cvsanaly; developers; evolution; freebsd; gimp; gnome; kde; mono; mozilla

Core and periphery in Free/Libre and Open Source software team communications - Kevin Crowston; Kangning Wei; Li, Qing; Howison, James (Proceedings of the 39th Annual Hawaii International Conference on System Sciences-Volume 06, 2006)
The concept of the core group of developers is important and often discussed in empirical studies of FLOSS projects. This paper examines the question, "how does one empirically distinguish the core?" Being able to identify the core members of a FLOSS development project is important because many of the processes necessary for successful projects likely involve core members differently than peripheral members, so analyses that mix the two groups will likely yield invalid results. We compare 3 analysis approaches to identify the core: the named list of developers, a Bradford's law analysis that takes as the core the most frequent contributors and a social network analysis of the interaction pattern that identifies the core in a core-and-periphery structure. We apply these measures to the interactions around bug fixing for 116 SourceForge projects. The 3 techniques identify different individuals as core members; examination of which individuals are identified leads to suggestions for refining the measures. All 3 measures though suggest that the core of FLOSS projects is a small fraction of the total number of contributors.
Keywords: bug fixing; contributions; contributors; core; developers; social network analysis; sourceforge; team

Critical Success Factors for Migrating to OSS-on-the-Desktop: Common Themes across Three South African Case Studies - Brink, Daniel; Roos, Llewelyn; Weller, James; Van Belle, Jean-Paul (OSS2006: Open Source Systems (IFIP 2.13), 2006)
This paper investigates the critical success factors associated with the migration from proprietary desktop software to an open source software (OSS) desktop environment in a South African context. A comparative case study analysis approach was adopted whereby three organisations that have migrated to desktop OSS were analysed. For diversity, one case study each was drawn from government, private industry and the educational sector. Most of the findings agree with those in the available literature though there are notable differences in the relative importance of certain factors.

Detecting similar Java classes using tree algorithms - Sager, Tobias; Bernstein, Abraham; Pinzger, Martin; Kiefer, Christoph (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
Similarity analysis of source code is helpful during development to provide, for instance, better support for code reuse. Consider a development environment that analyzes code while typing and that suggests similar code examples or existing implementations from a source code repository. Mining software repositories by means of similarity measures enables and enforces reusing existing code and reduces the developing effort needed by creating a shared knowledge base of code fragments. In information retrieval similarity measures are often used to find documents similar to a given query document. This paper extends this idea to source code repositories. It introduces our approach to detect similar Java classes in software projects using tree similarity algorithms. We show how our approach allows to find similar Java classes based on an evaluation of three tree-based similarity measures in the context of five user-defined test cases as well as a preliminary software evolution analysis of a medium-sized Java project. Initial results of our technique indicate that it (1) is indeed useful to identify similar Java classes, (2)successfully identifies the ex ante and ex post versions of refactored classes, and (3) provides some interesting insights into within-version and between-version dependencies of classes within a Java project.
Keywords: change analysis; clones; coogle; eclipse; famix; java; similarity; software evolution; software repositories; source code; tree similarity measures

Developer Learning Dynamics in Open Source Software Projects: A Hidden Markov Model Analysis - Param Vir Singh; Nara Youn; Yong Tan (2006)
This work proposes a dynamic model of developer learning in open source software (OSS) projects. A Hidden Markov Model (HMM) is proposed to explain how the code contribution behaviors of OSS de-velopers change as their levels of knowledge on their projects increase. In this model, discrete hidden states represent the unobserved knowledge levels of developers, and their observed code contribution be-haviors are modeled as state dependent. Developers??? knowledge levels evolve as they learn about the pro-jects over time. Two modes of learning are considered: learning-by-doing (code development) and learn-ing through interactions with peers. The model is calibrated using data spanning six years for 25 OSS pro-jects and 251 developers hosted at Sourceforge. The proposed model identifies three knowledge states (high, medium, and low) and estimates the impact of the two modes of learning on the transition of devel-opers between the three knowledge states. The model results suggest that in the low knowledge state de-velopers exhibit the greatest inertia, followed by those in the medium and high states. Both modes of learning are found to have varying impact across the three knowledge states. Interactions with peers ap-pear to be an important source of learning for developers in all states. A developer in the low state learns only through participation in threads started by others. Prior code contribution and starting discussion by initiating threads do not impact the knowledge level of a developer in the low state. Initiating threads, par-ticipating in threads started by others, and prior code contributions have positive impacts on the knowl-edge level of a developer in the medium or high state and, hence, influence his long term code contribu-tion behavior. Explanations for these varying impacts of learning activities on the transitions of develop-ers between the three states are provided. We also find a lack of persistence of knowledge in all states. The HMM better describes the data than a latent class model which would suggests that the learning ac-tivities have a long term, dynamic impact, rather than an immediate, static impact on the code contribu-tion behavior of a developer.

Development Platforms as a Niche for Software Companies in Open Source Software - Savonnet, Marinette; Leclercq, Eric; Terrasse, Marie-Noëlle; Grison, Thierry; Becker, George; Farizy, Anne; Denoyelle, Ludovic (OSS2006: Open Source Systems (IFIP 2.13), 2006)
Without Abstract

Discovering, Modeling, and Reenacting Open Source Software Development Processes - Chris Jensen; Walt Scacchi (New Trends in Software Process Modeling, 2006)

The Economical Aspects of Free Software and Open Source Software Solutions in Modern Business - Borucki, Blazej (Master thesis, under direction of dr. Konrad Wozniacki, 2006)
In the study economical aspects of Free / Open Source Software applications in commercial environment have been examined including main differences of commercial software development projects versus FOSS. Courtesy of Computer Science & Engineering department of University of Notre Dame statistical data from sourceforge.net projects have been analysed to show advantages and features of FOSS development. Empirical study also supports possible business models and strategies based on FOSS usage.

Effort Estimation by Characterizing Developer Activity - Amor, Juan Jose; Gregorio Robles; Jesus M. Gonzalez-Barahona (Proceedings of the 2006 International Workshop on Economics Driven Software Engineering Research, 2006)
During the latest years libre (free, open source) software has gained a lot of attention from the industry. Following this interest, the research community is also studying it. For instance, many teams are performing quantitative analysis on the large quantity of data which is publicly available from the development repositories maintained by libre software projects. However, not much of this research is focused on cost or effort estimations, despite its importance (for instance, for companies developing libre software or collaborating with libre software projects), and the availability of some data which could be useful for this purpose. Our position is that classical effort estimation models can be improved from the study of these data, at least when applied to libre software. In this paper, we focus on the characterization of developer activity, which we argue can improve effort estimation. This activity can be traced with a lot of detail, and the resulting data can also be used for validation of any effort estimation model.
Keywords: developer characterization; effort estimation; mining software repositories; open source software; software economics

Emergent decision-making practices in technology-supported self-organizing distributed teams - Robert Heckman; Kevin Crowston; Li, Qing; Eileen Allen; Eseryel, U. Yeliz; James Howison; Wei, Kangning (the International Conference on Information Systems (ICIS 2006), 2006)

Emergent Decision-making Practices in Technology-Supported Self-Organizing Distributed Teams - Robert Heckman; Kevin Crowston; Li, Qing; Eileen Allen; Eseryel, U. Yeliz; James Howison (Twenty Seventh International Conference on Information Systems, 2006)
We seek to identify work practices that make technology-supported self-organizing distributed (or virtual) teams (TSSODT for short) effective in producing outputs satisfactory to their sponsors, meeting the needs of their members and continuing to function. A particularly important practice for team effectiveness is decision making: are the right decisions made at the right time to get the work done in a way that satisfies team sponsors, keeps contributors happy and engaged, and enables continued team success? In this research-in-progress paper, we report on an inductive qualitative analysis of 120 decision episodes taken by 2 Free/libre Open Source Software development teams (the completed paper will include 360 episodes from 6 teams). Our analysis revealed differences in the performance of the two teams that seems to be related to differences in overall project effectiveness.

Empirical Software Engineering Research on Free/Libre/Open Source Software - Gregorio Robles (Proceedings of the 22nd IEEE International Conference on Software Maintenance, 2006)
Public available data sources are an important knowledge generator from which researchers can obtain, mostly in a non-intrusive way, data and facts from software projects. We present a methodological approach to the data sources commonly found in libre (free, open source) software projects over the Internet, explain how to extract these data and enhance them and offer some ways of analyzing it from various perspectives. The whole process has been implemented with tools that automatize the process so that an ample amount of analysis from various angles (that range from software maintenance and software evolution to the social structure of the underlying organization in charge of the development) of a huge amount of software projects has been used as case studies. This work demonstrates that it is possible to build research methodologies that can be applied to a large quantity of software projects and that empirical software engineering studies have not to refer to a limited number of software projects. Although specifically targeted to libre software development, many of the techniques and lessons learned can be generally applied to other types of software environments.

An Empirical Study on Implementing FLOSS in Schools - Yu-wei Lin; Enrico Zini (Social Informatics: An Information Society for All? In Remembrance of Rob Kling, the proceedings of the 7th 'Human Choice and Computers' conference, 2006)
This empirical paper shows how free/libre open source software (FLOSS) contributes to mutual and collaborative learning in an educational environment. Unlike proprietary software, FLOSS allows extensive customisation of software and supports the needs of local users better. In this paper, we observes how implementing FLOSS in an Italian high school challenges the conventional relationship between end users themselves (e.g. teachers and students) and that between users and developers. The findings will shed some light on the social aspects of FLOSS-based computerization - including the role of FLOSS in social and organizational change in educational environments and the ways that the social organization of FLOSS are influenced by social forces and social practices.

An Empirical Study on the Migration to OpenOffice.org in a Public Administration - Rossi, B.; Scotto, M.; Sillitti, A.; Succi, G. (International Journal of Information Technology and Web Engineering, 2006)
The aim of the article is to report the results of a migration to Open Source Software (OSS) in one public administration. The migration focuses on the office automation field and, in particular, on the OpenOffice.org suite. We have analysed the transition to OSS considering qualitative and quantitative data collected with the aid of different tools. All the data have been always considered from the point of view of the different stakeholders involved, IT managers, IT technicians, and users. The results of the project have been largely satisfactory. However the results cannot be generalised due to some constraints, like the environment considered and the parallel use of the old solution. Nevertheless, we think that the data collected can be of valuable aid to managers wishing to evaluate a possible transition to OSS.

The evolution of free/libre open source software - Lorenzo Benussi (2006)
The Free Libre Open Source Software represents an outstanding example of ???open development model of technological knowledge???. It has been studied in several researches that produced valuable illustrations of the way it works. Our understanding of its principal features is growing exponentially and an entire new literature on open source has been created. However there appears to be an important gap in the literature: the origin of the phenomenon. The following chapter attempts to tackle this issue by analyzing the long-term technological history of the Free Open Source Software; the main research questions at stake are: ???Is the phenomenon completely new? and if it is not totally new, where does it come from???? and, more generally, ???how did open source software developed over time????. As a consequence the present work focuses primarily on the analysis of the free/open source software history of technological change over a period of almost sixty years. I adopted a multidisciplinary approach to analyse the network of relations emerging between inventions and technological innovations, as well as economic determinants and intellectual property rights regimes throughout the period considered. Therefore, I attempted to investigate the origins of the phenomenon as a way of understanding its evolution.

Evolution of Open Source Communities - Weiss, Michael; Moroiu, Gabriella; Zhao, Ping (OSS2006: Open Source Systems (IFIP 2.13), 2006)
The goal of this paper is to document the evolution of a portfolio of related open source communities over time. As a case study, we explore the subprojects of the Apache project, one of the largest and most visible open source projects. We extract the community structure from the mailing list data, and study how the subcommunities evolve, and are interrelated over time. Our analysis leads us to propose the following hypotheses about the growth of open source communities: (1) communities add new developers by a process of preferential attachment; (2) links between existing communities are also subject to preferential attachment; (3) developers will migrate between communities together with other collaborators; and (4) information flow follows project dependencies. In particular, we are concerned with the underlying factors that motivate the migration between communities, such as information flow, co-worker ties, and project dependencies.
Keywords: apache; COMMUNITY; core; developers; email; email archives; mailing list; membership

The evolution radar: visualizing integrated logical coupling information - D'Ambros, Marco; Lanza, Michele; Lungu, Mircea (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
In software evolution research logical coupling has extensively been used to recover the hidden dependencies between source code artifacts. They would otherwise go lost because of the file-based nature of current versioning systems. Previous research has dealt with low-level couplings between files, leading to an explosion of data to be analyzed, or has abstracted the logical couplings to module level, leading to a loss of detailed information. In this paper we propose a visualization-based approach which integrates both file-level and module-level logical coupling information. This not only facilitates an in-depth analysis of the logical couplings at all granularity levels, it also leads to a precise characterization of the system modules in terms of their logical coupling dependencies.
Keywords: change management; cvs; evolution; logical coupling; mozilla; scm; source code; thunderbird; tinderbox; visualization

Examining the evolution of code comments in PostgreSQL - Zhen Ming Jiang; Hassan, Ahmed E. (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
It is common, especially in large software systems, for developers to change code without updating its associated comments due to their unfamiliarity with the code or due to time constraints. This is a potential problem since outdated comments may confuse or mislead developers who perform future development. Using data recovered from CVS, we study the evolution of code comments in the PostgreSQL project. Our study reveals that over time the percentage of commented functions remains constant except for early fluctuation due to the commenting style of a particular active developer.
Keywords: code comments; comments; cvs; evolution; functions; maintenance; mining challenge; msr challenge; postgresql; software evolution; software maintenance; source code

Exit & Voice in Free & Open Source Software Licensing: Moderating the Rein over Software Users - Greg R Vetter (2006)
This article analyzes the interplay between exit and voice for user adoption of Free and Open Source Software (FOSS), as these two are conceptualized in Albert O. Hirschman's book Exit, Voice, and Loyalty: Responses to Decline in Firms, Organizations and States. Exit and voice cooperatively sustain FOSS through the institutional mechanism of the FOSS license. Four situations demonstrate this. First, even with attendant uncertainties in its novel legal landscape, users adopt FOSS to escape proprietary licensed software. This exit is tinged with indirect voice. Second, this indirect voice arises from collaborative projects to develop FOSS. The very same code and license that provides the exit carries the voice. Third, complementing exit by users are technologists who contribute, extracurricularly, to open source projects, signaling their affiliation with FOSS. Fourth, from its beginning, the FOSS movement has expressed its voice. Its norm entrepreneurs use rhetoric and persuasion to reinforce FOSS's disciplining effect on an entire industry. These four situations highlight exit and voice combinations for copyright based open source licensing and patent law. The FOSS copyright based licensing scheme helps channel FOSS into uses where exit and voice are concentrated and synergistically reinforce. The interplay with patent law generates voice because patent law, at least theoretically, inhibits exit to FOSS and thus pressurizes the voice mechanism in Hirschman's framework. Understanding FOSS based combinations of exit and voice in light of this framework helps participants and policy makers formulate legal, licensing and policy strategies to guide the movement and respond to its evolution.

Experiences in Automating the Analysis of Linguistic Interactions for the Study of Distributed Collectives - Gabriel Ripoche; Sansonnet, Jean-Paul (Computer Supported Cooperative Work (CSCW), 2006)
An important issue faced by research on distributed collective practices is the amount and nature of the data available for study. While persistent mediated interaction offers unprecedented opportunities for research, the wealth and richness of available data pose issues on their own, calling for new methods of investigation. In such a context, automated tools can offer coverage, both within and across collectives. In this paper, we investigate the potential contributions of semantic analyses of linguistic interactions for the study of collective processes and practices. In other words, we are interested in discovering how linguistic interaction is related to collective action, as well as in exploring how computational tools can make use of these relationships for the study of distributed collectives.
Keywords: flossmole cited

Exploring the potential of OSS in Air Traffic Management - Hardy, Jean-Luc; Bourgois, Marc (OSS2006: Open Source Systems (IFIP 2.13), 2006)
This paper introduces a project that aims at defining an Open Source Software (OSS) policy in the field of Air Traffic Management (ATM). In order to develop such a policy, we chose to investigate first a set of predictive hypotheses. Our four initial hypotheses were presented, refined and discussed in bi-lateral meetings with experts in the ATM field and in several conferences and workshops with OSS experts. At a roundtable, jointly organized by CALIBRE and EUROCONTROL, we confronted early open source experiences and insights in the ATM domain with experiences and knowledge from a panel of OSS experts and practitioners from academia and industry. The revised initial hypotheses are presented using a fixed format that should facilitate further evolution of these hypotheses.

Fine grained indexing of software repositories to support impact analysis - Canfora, Gerardo; Cerulo, Luigi (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
Versioned and bug-tracked software systems provide a huge amount of historical data regarding source code changes and issues management. In this paper we deal with impact analysis of a change request and show that data stored in software repositories are a good descriptor on how past change requests have been resolved. A fine grained analysis method of software repositories is used to index code at different levels of granularity, such as lines of code and source files, with free text contained in software repositories. The method exploits information retrieval algorithms to link the change request description and code entities impacted by similar past change requests. We evaluate such approach on a set of three open-source projects.
Keywords: argouml; change analysis; Firefox; gedit; impact analysis; mining software repositories; scm; source code; version control

FLOSSmole: A Collaborative Repository for FLOSS Research Data and Analyses - James Howison; Conklin, Megan; Kevin Crowston (International Journal of Information Technology and Web Engineering, 2006)

The FLOSSWALD information system on free and open source software - Reichle, M.; Hanft, A. (9th International Workshop on Learning Software Organizations, 2006)
We propose the implementation of an intelligent information system on free and open source software. This system will consist of a case-based reasoning (CBR) system and several machine learning modules to maintain the knowledge base and train the CBR system thus enhancing its performance. Our knowledge base will include data on free and open source software provided by the Debian project, the FLOSSmole project, and other public free and open source software directories. We plan to enrich these data by learning additional information such as concepts and different similarities. With this knowledge base, we hope to be able to create an information system that will be capable of answering queries based on precise as well as vague criteria and give intelligent recommendations on software based on the preferences of the user.
Keywords: debian; flossmole

A Framework for Teaching Software Testing using F/OSS Methodology - Sowe, Sulayman; Ioannis Stamelos; Deligiannis, Ignatios (OSS2006: Open Source Systems (IFIP 2.13), 2006)
In this paper we discuss a framework for teaching software testing to undergraduate students’ volunteers. The framework uses open source software development methodology and was implemented in the “Introduction to Software Engineering” course at the department of Informatics, Aristotle University, Greece. The framework is in three phases, each describing a teaching and learning context in which students get involved in real software projects activities. We report on our teaching experiences, lessons learned and some practical problems we encountered. Results from preliminary evaluation shows that students did well as bug hunters in the bazaar and are willing to participate in their projects long after graduation.

Free and open source software hackers in Turkey - Ibrahim Izlem Gozukeles (n/a, 2006)
In recent years, there has been growing interest of governments and firms for Free and Open Source Software (FOSS). However, FOSS is still a puzzlement for a wide spectrum of academic disciplines. Social scientists ask why FOSS hackers participate in FOSS if they do not get any monetary rewards. On the other hand firms ask, how a firm can earn money from FOSS. In this study, motivations of FOSS hackers and firms are taken as an interrelated phenomenon. This study discusses FOSS from the view of hackers in Turkey. In that respect, social conditions that make hackers voluntarily contribute to the FOSS projects and their relationship with the commercial world are explored. 1

Free Open Source as a Technology Transfer Tool in the Arab World - Jamil Alkhatib (2006)
The Arab world has so far minimum contribution to the current global innovation system. Technology transfer is a major factor behind such weakness. Within the context of the Arab world, the Free Open Source (FOS)process could be adopted as a cheap and fast alternative tool for technology transfer. This study will focus on the effectiveness of FOS process on the Technology Transfer and how it will improve the cooperation between research and industrial institutes working in the ICT sector in the Arab world.

Free/Open Source Software And Business: Forming A Migration Policy - Kristijan Spirov (2006)
This paper explores the non-technical issues that arise with migration to Free/Libre and Open Source Software (FLOSS) in Large Scaled Enterprises (LSEs), with special emphasis on human and social issues. The result of the study is a conceptual framework for effective addressing of non-technical issues in a migration policy. The study is of exploratory nature and uses secondary research findings from multiple disciplines: free and open source software, management of human resources, power and conflict, system migration, information systems development, motivation, change management, organizational psychology and social informatics; including anecdotal evidence from FLOSS migrations in practice. A holistic approach has been used during the analysis of the migration issues, based on the key principles of social informatics that IT technology and social contexts are interdependent. The relationship between FLOSS migrations and different organizational contexts is elaborated and it has been found out how lack of vendor support for FLOSS motivates LSEs to improve their self-support of own IT infrastructures. In-depth analysis is performed of the individual and social impact that FLOSS migrations have on enterprise IT personnel, as well as how different individual factors such as age, gender, personal motivations and beliefs may impact on individual migration efforts. The social differences between typical enterprise IT personnel and the FLOSS community are elaborated, as well as how to overcome the communication gap between them. The role of end users in FLOSS migration and relevant issues are discussed. It is proved why staged migration is the most viable option and it is shown how it is related to human and social factors. At the end, a conceptual framework for description of non-technical FLOSS migration issues is discussed, which can be used as a helpful tool in a migration policy.

From Individual Contribution to Group Learning - Hala Annabi; Kevin Crowston; Robert Heckman (OSS2006: Open Source Systems (IFIP 2.13), 2006)
Open Source Software (OSS) groups experience many benefits and challenges with respect to the core group’s effectiveness. In order to capitalize on the benefits and minimize the challenges, OSS groups must learn not only on the individual level, but also on the group level. OSS groups learn by integrating individual contributions into the group’s product and processes. This paper reports on the characteristics of the learning process in OSS groups. The study utilized an embedded single case study design that observed and analyzed group learning processes in the Apache Web server OSS project. The study used learning opportunity episodes (LOE) as the embedded unit of analysis and developed and utilized three content analytic schemes to describe the characteristics of the learning process and the factors affecting this process.
Keywords: apache; case study

Geographic location of developers at SourceForge - Gregorio Robles; Jesus M. Gonzalez-Barahona (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
The development of libre (free/open source) software is usually performed by geographically distributed teams. Participation in most cases is voluntary, sometimes sporadic, and often not framed by a pre-defined management structure. This means that anybody can contribute, and in principle no national origin has advantages over others, except for the differences in availability and quality of Internet connections and language. However, differences in participation across regions do exist, although there are little studies about them. In this paper we present some data which can be the basis for some of those studies. We have taken the database of users registered at SourceForge, the largest libre software development web-based platform, and have inferred their geographical locations. For this, we have applied several techniques and heuristics on the available data (mainly e-mail addresses and time zones), which are presented and discussed in detail. The results show a snapshot of the regional distribution of SourceForge users, which may be a good proxy of the actual distribution of libre software developers. In addition, the methodology may be of interest for similar studies in other domains, when the available data is similar (as is the case of mailing lists related to software projects).
Keywords: distributed; email; email address; free software; geographical location; geography; libre software; mining software repositories; open source software; sourceforge; timezone

A graphical installation system for the GNU/Linux Debian distribution - Attilio, Fiandrotti; Di Nunzio, Pierluigi; Di Gregorio, Federico; Meo, Angelo (OSS2006: Open Source Systems (IFIP 2.13), 2006)
One of the main objectives of the Centro di Competenza sul Software Libero del Politecnico di Torino is to provide custom GNU/Linux distribution to the Public Administration, small and medium enterprise and schools. Debian GNU/Linux was choosen as the base for the custom distributions because of its strong support of free software and its long-standing technical merits: minimalist hardware requirement, the best available packaging system, support for 13 different architectures and a strict set of quality guidelines adopted by all the active Debian developers. The only foreseeable limitation, the Debian default text-based installer, was overriden by restarting the development of the then-abandoned Debian graphical installer. Now the new graphical installer is developed by tens of people and it will be included in the next official Debian release.

Hierarchy and centralization in Free and Open Source Software team communications - Kevin Crowston; Howison, James (Knowledge, Technology & Policy, 2006)
Free/Libre Open Source Software (FLOSS) development teams provide an interesting and convenient setting for studying distributed work. We begin by answering perhaps the most basic question: what is the social structure of these teams? Based on a social network analysis of interactions represented in 62,110 bug reports from 122 large and active projects, we find that some OSS teams are highly centralized, but contrary to expectation, others are not. Projects are mostly quite hierarchical on four measures of hierarchy, consistent with past research but contrary to the popular image of these projects. Furthermore, we find that the level of centralization is negatively correlated with project size, suggesting that larger projects become more modular. The paper makes a further methodological contribution by identifying appropriate analysis approaches for interaction data. We conclude by sketching directions for future research.
Keywords: apache; bug fixing; bug tracking; FLOSS; project success; savannah; social network analysis; sourceforge; team size; teams

How free software developers work. The mobilization of "distant communities" - Didier Demazière; Francois Horn; Nicolas Jullien (2006)
The work of free software developers is an individual activity carried out in extremely heterogeneous conditions and a collective action with original production methods. We propose to analyze this work starting with the paradoxical notion of a "distant community", that aims to illustrate the tension between, on the one hand, the strength of the sense of belonging to a specific world identifiable in the discourse of the participants and, on the other hand, the distances that separate the contributors in terms of relationships, status, and background. In doing this the aim is to produce a description, necessarily plural, of the different forms of "distant communities" that enables the production of goods in unique social and organizational conditions. More generally speaking, this notion points to methods of coordination that combine two forms of collective action that are usually contrary and antagonistic: a communitarian form based on the subjective feeling of belonging to the same community and a form of partnership based on the coordination of common interests and sharing of objectives (T??nnies, 1887, Weber, 1921). At first, we examine the ways the individual participants organize themselves in order to contribute to a project and we focus on the forms of cooperation and coordination used to deal with the constraints of efficiency and quality associated with the distribution of a product. Secondly, we look at the other side of the coin and examine the ways individual participants take action and we underline the mechanisms of commitment and participation that account for their contribution to the production of free software. These two dimensions, that in our opinion are inseparable, are explored through a survey carried out with free software developers.

How is it possible to profit from innovation in the absence of any appropriability? - Andrea Bonaccorsi; Lucia Piscitello; Monica Merito; Cristina Rossi (OSS2006: Open Source Systems (IFIP 2.13), 2006)
Open Source Software (OSS) represents an “open innovation” paradigm based on knowledge produced and shared by developers and users. New findings from a large survey of European software companies show that: (i) the OSS business model is currently involving almost one third of the industry, although with different intensity; (ii) compared with pure proprietary software producers, OSS firms have a broader product portfolio and are more diversified; moreover, (iii) OSS firms provide more complementary services to their customers; (iv) over time OSS firms increase the share of OS turnover out of the total turnover, becoming more and more OSS oriented; (v) both NOSS and OSS firms do not consider appropriability as a crucial requirement for innovation and do not consider the lack of appropriability as an obstacle to profitability.

How long did it take to fix bugs? - Kim, Sunghun; Whitehead,Jr., E. James (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
The number of bugs (or fixes) is a common factor used to measure the quality of software and assist bug related analysis. For example, if software files have many bugs, they may be unstable. In comparison, the bug-fix time--the time to fix a bug after the bug was introduced--is neglected. We believe that the bug-fix time is an important factor for bug related analysis, such as measuring software quality. For example, if bugs in a file take a relatively long time to be fixed, the file may have some structural problems that make it difficult to make changes. In this report, we compute the bug-fix time of files in ArgoUML and PostgreSQL by identifying when bugs are introduced and when the bugs are fixed. This report includes bug-fix time statistics such as average bug-fix time, and distributions of bug-fix time. We also list the top 20 bug-fix time files of two projects.
Keywords: argouml; bug fixing; bugs; mining challenge; msr challenge; postgresql; quality; time

Identification of coordination requirements: Implications for the design of collaboration and awareness tools - Cataldo, Marcelo; Wagstrom, Patrick A.; Herbsleb, J. D.; Carley, Kathleen M. (Conference on Computer Support Collaborative Work, 2006)
Keywords: modularity

Identifying Knowledge Brokers that Yield Software Engineering Knowledge in OSS Projects - Sowe, Sulayman K.; Ioannis Stamelos; Lefteris Angelis (Information and Software Technology, 2006)
Much research on open source software development concentrates on developer lists and other software repositories to investigate what motivates professional software developers to participate in open source software projects. Little attention has been paid to individuals who spend valuable time in lists helping participants on some mundane yet vital project activities. Using three Debian lists as a case study we investigate the impact of knowledge brokers and their associated activities in open source projects. Social network analysis was used to visualize how participants are affiliated with the lists. The network topology reveals substantial community participation. The consequence of collaborating in mundane activities for the success of open source software projects is discussed. The direct beneficiaries of this research are in the identification of knowledge experts in open source software projects.
Keywords: debian; email; email archives; expertise; knowledge sharing; mailing list; project success; social network analysis

The Impact of Ideology on Effectiveness in Open Source Software Development Teams - Stewart, K.; Gosain, S. (MIS Quarterly, 2006)
The emerging work on understanding open source software has argued for the importance of understanding what leads to effectiveness in OSS development teams and has pointed to the importance of ideology. This paper develops a framework of the OSS ideology (including specific norms, beliefs, and values) and a theoretical model to show how adherence to components of the ideology impact effectiveness in OSS teams. The model is based on the idea that ideology provides clan control, which is important in OSS development settings because OSS teams generally lack formal behavioral and outcome controls. The paper hypothesizes both direct effects of ideology on OSS team effectiveness and indirect effects via influences on affective trust, cognitive trust, and communication quality. Hypotheses are tested using survey and objective data on OSS projects. Four effectiveness measures are used to capture unique aspects of effectiveness in OSS including both the extent to which a team attracts input from the community and the team's success in accomplishing project outcomes. Results support the main thesis that OSS team members' adherence to the tenets of the OSS community ideology enhances OSS team effectiveness. The study uncovers several differences in the importance of OSS norms, beliefs, and values to different kinds of OSS team effectiveness and discusses implications for theory and practice.
Keywords: bug fixing; bug reports; bug tracking; communication; COMMUNITY; effectiveness; feature requests; ideology; metadata; sourceforge; Survey; team effort; team size; trust

Impact of Social Ties on Open Source Project Team Formation - Hahn, Jungpil; Moon, Jae; Zhang, Chen (OSS2006: Open Source Systems (IFIP 2.13), 2006)
In this paper, we empirically examined the role of social ties in OSSD team formation and developer joining behavior. We find that the existence and the amount of prior social relations in the network do increase the probability of an OSS project to attract more developers. Interestingly, for projects without preexisting social ties, developers tend to join the project initiated by people with less OSSD experience. This research fills a gap in the open source literature by conducting an empirical investigation of the role of social relations on project team formation behavior. Furthermore, the adoption of social network analysis, which has received little attention in the OSS literature, can yield some interesting results on the interactions among OSS developers.
Keywords: developers; metadata; social network analysis; sourceforge

Impacts of license choice and organizational sponsorship on user interest and development activity in open source software projects - Katherine Stewart; Ammeter, A. P.; Maruping, L. M. (Information Systems Research, 2006)
What differentiates successful from unsuccessful open source software projects? This paper develops and tests a model of the impacts of license restrictiveness and organizational sponsorship on two indicators of success: user interest in, and development activity on, open source software development projects. Using data gathered from Freshmeat.net and project home pages, the main conclusions derived from the analysis are that (1) license restrictiveness and organizational sponsorship interact to influence user perceptions of the likely utility of open source software in such a way that users are most attracted to projects that are sponsored by nonmarket organizations and that employ nonrestrictive licenses, and (2) licensing and sponsorship address complementary developer motivations such that the influence of licensing on development activity depends on what kind of organizational sponsor a project has. Theoretical and practical implications are discussed, and the paper outlines several avenues for future research.

Information systems success in Free and Open Source Software development: Theory and measures - Kevin Crowston; Howison, James; Hala Annabi (Software Process–Improvement and Practice, 2006)
Information systems success is one of the most widely used dependent variables in information systems (IS) research, but research on Free/Libre and Open Source software (FLOSS) often fails to appropriately conceptualize this important concept. In this paper, we reconsider what success means within a FLOSS context. We first review existing models of IS success and success variables used in FLOSS research and assess them for their usefulness, practicality and fit to the FLOSS context. Then, drawing on a theoretical model of group effectiveness in the FLOSS development process, as well as an online discussion group with developers, we present additional concepts that are central to an appropriate understanding of success for FLOSS. In order to examine the practicality and validity of this conceptual scheme, the second half of our paper presents an empirical study that demonstrates its operationalization of the chosen measures and assesses their internal validity. We use data from SourceForge to measure the project’s effectiveness in team building, the speed of the project at responding to bug reports and the project’s popularity. We conclude by discussing the implications of this study for our proposed extension of IS success in the context of FLOSS development and highlight future directions for research.
Keywords: bug fixing; developers; downloads; FLOSS; flossmole; page views; popularity; project success; size; sourceforge; success; team size

Information theoretic evaluation of change prediction models for large-scale software - Askari, Mina; Holt, Ric (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
In this paper, we analyze the data extracted from several open source software repositories. We observe that the change data follows a Zipf distribution. Based on the extracted data, we then develop three probabilistic models to predict which files will have changes or bugs. The first model is Maximum Likelihood Estimation (MLE), which simply counts the number of events, i.e., changes or bugs, that happen to each file and normalizes the counts to compute a probability distribution. The second model is Reflexive Exponential Decay (RED) in which we postulate that the predictive rate of modification in a file is incremented by any modification to that file and decays exponentially. The third model is called RED-Co-Change. With each modification to a given file, the RED-Co-Change model not only increments its predictive rate, but also increments the rate for other files that are related to the given file through previous co-changes. We then present an information-theoretic approach to evaluate the performance of different prediction models. In this approach, the closeness of model distribution to the actual unknown probability distribution of the system is measured using cross entropy. We evaluate our prediction models empirically using the proposed information-theoretic approach for six large open source systems. Based on this evaluation, we observe that of our three prediction models, the RED-Co-Change model predicts the distribution that is closest to the actual distribution for all the studied systems.
Keywords: bugs; change analysis; cvs; evaluation approach; file; freebsd; information theory; kde; koffice; log files; netbsd; openbsd; postgresql; prediction; prediction models; scm; source code

Insert Movie Reference Here: A System to Bridge Conversation and Item-Oriented Web Sites - Sara Drenner; Max Harper; Dan Frankowski; John Riedl; Loren Terveen (ACM SIGCHI Conference on Human Factors in Computing Systems, 2006)

Insiders and outsiders: paid contributors and the dynamics of cooperation in community led F/OS projects - Evangelia Berdou (OSS2006: Open Source Systems (IFIP 2.13), 2006)
This paper examines the role of paid developers in mature free/open source (F/OS) communities. In particular it provides a typology for their involvement based on their employment and sponsorship arrangements and elaborates a framework for understanding the dynamics of cooperation developing between them and the volunteers based on their community ties. The evidence presented is drawn from individual interviews conducted with volunteer and paid contributors from the GNOME and KDE projects within the context of a PhD research focusing on commercialization and peripheral participation in F/OS communities. The paper highlights the various interdependencies that form between communities and companies and adds to our understanding of the dynamics of commercialization in F/OS projects.
Keywords: gnome; interviews; kde

Institutional Entrepreneurs and the Bricolage of Intellectual Property Discourses - Westenholz, Ann (OSS2006: Open Source Systems (IFIP 2.13), 2006)
Commercial software firms are increasingly becoming involved with open source communities. In this research-in-progress paper I briefly analysed a single firm case that demonstrates how an institutional entrepreneur mixes in an innovative way different discourses in an attempt to legitimise a new mode for developing software applying both open and closed source codes. The institutional entrepreneur does this by creating new distinctions in his daily software developing work. I am not arguing that the institutional entrepreneur is creating these new distinctions in an instrumental rational process, but that the distinctions emerge in sensemaking processes along his ‘doing’ something in the firm.

Integration of libre software applications to create a collaborative work platform for researchers at GET - Olivier Berger; Christian Bac; Benoit Hamet (International Journal of Information Technology and Web Engineering, 2006)
Libre software provides powerful applications ready to be integrated for the build-up of platforms for internal use in organizations. We describe the architecture of the collaborative work platform which we have integrated, designed for researchers at GET. We present the elements we have learned during this project in particular with respect to contribution to external libre projects, in order to better ensure the maintainability of the internal applications, and to phpGroupware as a framework for specific applications development.
Keywords: collaborative work environment; contribution; free software; groupware; in-house applications; libre software; open source software; OpenLDAP; phpGroupware; PicoLibre; ProGET; Sympa; TWiki; WebDAV; wiki

'Intellectual Property' and Knowledge Creation in Disorganisations - Tere Vadén (2006)
Given the current forms of economic production and corporate markets, the liberating and democratic potential of digital information is counteracted by the concentration of media ownership, as well as by policy, legislation, and the development of proprietary forms of technology. The notion of 'intellectual property' produces artificial scarcity where digital technology could remove it. This tension between the proprietary and non-proprietary aspects of the information society can be analysed by looking at two types of knowledge creation: organisational and disorganisational. While organisational knowledge work can benefit from a notion of 'intellectual property', disorganisational knowledge work is disrupted, if not destroyed, by proprietary barriers on information. This is unfortunate if and when the crucial innovations and ethical potential of the information society are connected to disorganisational communities, even though the organisational type is more visible and better represented in the traditional structures of society.

The Introduction of OpenOffice.org in the Brussels Public Administration - Ven, Kris; Van Nuffel, Dieter; Verelst, Jan (OSS2006: Open Source Systems (IFIP 2.13), 2006)
Open source software is increasingly used by public administrations as an alternative to commercial software. In this paper we present a case study of the transition of the ministerial cabinets of the Brussels-Capital Region towards OpenOffice.org. In this case, the decision to use open source software was taken by the Government of the Brussels-Capital Region. The goal of the paper is to outline the implementation trajectory followed and to compare our findings to previous studies in this field as well as other Information Systems literature. Additionally, we discuss how OpenOffice.org was received by end users as well as the IT department that was responsible for the migration. Our findings indicate that although a migration towards OpenOffice.org is feasible, a number of difficulties still remain. For example, end user perceptions of OpenOffice.org are not always favorable and migration costs (document conversion and training) can be significant.

Knowledge Reuse in Open Source Software: An Exploratory Study of 15 Open Source Projects - von Krogh, G.; Spaeth, S.; Haefliger, S. (Proceedings of the 38th Annual Hawaii International Conference on System Sciences, 2006)
To date, there is no investigation of knowledge reuse in open source software projects. This paper focuses on the forms of knowledge reuse and the factors impacting on them. It develops a theory drawn from data of 15 open source software projects and finds that the effort to search, integrate and maintain external knowledge influences the form of knowledge to be reused. Implications for firms and innovation research are discussed.
Keywords: cvs; email; knowledge reuse; lines of code; loc; source code; Survey

Learning and knowledge in FLOSS - Situated learning and organizational knowledge-conversion in community-based free/libre open source software development - Sverre Helge Bolstad (2006)
In free/libre open source software development (FLOSS), groups of developers and users working in geographically dispersed settings are supported by a dense network of interactions. The participants are highly skilled in the use of information- and communication technologies, and build the software by relying on extensive peer production and through skillful use of communication tools available on the Internet. In building the software, explicit, formal and structured knowledge in the form of documents, objects, machines and external sources are communicated and stored in ways that make it available for others in the present and future. This knowledge make up an important resource for the members and developers of the community. Another kind, or aspect, of knowledge, often called tacit or soft knowledge, is informal, unstructured, resides in people, and are difficult, or maybe impossible, to articulate. The questions guiding this research is how knowledge, both explicit and tacit, is shared, and how a new member is able take part in the practice and knowledge of the community. The theory of legitimate peripheral participation in communities of practice describes an environment for people to develop knowledge through interaction with others in an environment where knowledge is created, nurtured and sustained. By taking part in the practice as a participant observer, through virtual ethnography, the author describes the practice and communication in this decentralized and knowledge-intensive process. Taking it a step further, the knowledge of the community, and how it is shared within the ???organization???, is explored with a model for managing dynamic aspects of organizational knowledge-creation. The central theme here is that knowledge is created through a continuous dialogue between tacit and explicit knowledge. Logs from Internet Relay Chat (IRC) and interviews with core developers are analyzed, and the author argues that the Plone community is able to share both kinds of knowledge in a complex web of resources and interaction. The analysis further suggest that the FLOSS development-model facilitates access, transparency and participation on premisses that are important for learning.

Licensing Services: An “Open” Perspective - D’Andrea, Vincenzo; Gangadharan, G. (OSS2006: Open Source Systems (IFIP 2.13), 2006)
Though service orientation is an incipient technology, the inherently infinite potentiality of services makes them to proliferate seamlessly, serving in myriad domains. Licensing of services enables to regulate the commercial use and modifications of service, retaining the copyright with owner of the service. With the growing influence of open source initiatives today, it becomes a significant topic to analyze ‘open’ing services. In this paper, we present a concept of ‘open service’ and analyze the implications of open source approach on service licenses.

Life cycle of Defects in Open Source Software Projects - Koponen, Timo (OSS2006: Open Source Systems (IFIP 2.13), 2006)
We studied the maintenance process from the viewpoint of defect management and the defect life cycle. First, we outline a model for the defect life cycle based on ISO/IEC standards, the Framework for Open Source maintenance process, and the Bugzilla defect management system. Thereafter, we analyze defects from two Open Source software projects. The aim of the study was support the maintenance reliability. However, we found that most of the defects did not follow the life-cycle model. Defects were usually directly resolved from initial state without being assigned.
Keywords: apache; defects; Firefox; mozilla

Location, Location, Location: How Network Embeddedness Affects Project Success in Open Source Systems - Grewal, Rajdeep; Lilien, Gary L.; Mallapragada, Girish (Management Science, 2006)
The community-based model for software development in open source environments is becoming a viable alternative to traditional firm-based models. To better understand the workings of open source environments, we examine the effects of network embeddedness---or the nature of the relationship among projects and developers---on the success of open source projects. We find that considerable heterogeneity exists in the network embeddedness of open source projects and project managers. We use a visual representation of the affiliation network of projects and developers as well as a formal statistical analysis to demonstrate this heterogeneity and to investigate how these structures differ across projects and project managers. Our main results surround the effect of this differential network embeddedness on project success. We find that network embeddedness has strong and significant effects on both technical and commercial success, but that those effects are quite complex. We use latent class regression analysis to show that multiple regimes exist and that some of the effects of network embeddedness are positive under some regimes and negative under others. We use project age and number of page views to provide insights into the direction of the effect of network embeddedness on project success. Our findings show that different aspects of network embeddedness have powerful but subtle effects on project success and suggest that this is a rich environment for further study.
Keywords: affiliation network; age; developers; latent class analysis; network embeddedness; open source software; page views; perl; project success; registration; sourceforge

Maintainability of the kernels of open-source operating systems: A comparison of Linux with FreeBSD, NetBSD, and OpenBSD - Yu, Liguo; Schach, Stephen R.; Chen, Kai; Heller, Gillian Z.; Offutt, Jeff (J. Syst. Softw., 2006)
We compared and contrasted the maintainability of four open-source operating systems: Linux, FreeBSD, NetBSD, and OpenBSD. We used our categorization of common coupling in kernel-based software to highlight future maintenance problems. An unsafe definition is a definition of a global variable that can affect a kernel module if that definition is changed. For each operating system we determined a number of measures, including the number of global variables, the number of instances of global variables in the kernel and overall, as well as the number of unsafe definitions in the kernel and overall. We also computed the value of each our measures per kernel KLOC and per KLOC overall. For every measure and every ratio, Linux compared unfavorably with FreeBSD, NetBSD, and OpenBSD. Accordingly, we are concerned about the future maintainability of Linux.
Keywords: abiword; Common coupling; coupling; Definition-use analysis; freebsd; kernel; lines of code; linux; linux kernel; loc; Maintainability; modules; netbsd; Open-source software; openbsd; source code

A man on the inside: Unlocking communities as complementary assets - Linus Dahlander; Martin W. Wallin (2006)
Since Teece's seminal paper explaining who were the gainers from technological innovation, increased globalization and the information and communication technology revolution have brought newways for firms to organize and appropriate from innovation. A new more open model of innovation suggests that firms can benefit from sources of innovation that stem from outside the firm. The central theme of this paper is how firms try to unlock communities as complementary assets. These communities exist outside firm boundaries beyond ownership or hierarchical control. Because of practices developed by communities to protect their work, firms need to assign individuals to work in these communities in order to gain access to developments and, to an extent, influence the direction of the community. Using network analysis we show that some software firms sponsor individuals to act strategically within a free and open source software (FOSS) community. Firm sponsored individuals interact with more individuals than interact with them, and also they seek to interact with central individuals in the community. However, we can see differences in how individuals interact, depending on whether their affiliation is with a dedicated FOSS firm or an incumbent in the software industry. Apparently, some firm managers believe they need ???a man on the inside??? to be able to gain access to communities. PLEASE EMAIL IF YOU LIKE A COPY OF THE PAPER!

MAPO: mining API usages from open source repositories - Xie, Tao; Pei, Jian (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
To improve software productivity, when constructing new software systems, developers often reuse existing class libraries or frameworks by invoking their APIs. Those APIs, however, are often complex and not well documented, posing barriers for developers to use them in new client code. To get familiar with how those APIs are used, developers may search the Web using a general search engine to find relevant documents or code examples. Developers can also use a source code search engine to search open source repositories for source files that use the same APIs. Nevertheless, the number of returned source files is often large. It is difficult for developers to learn API usages from a large number of returned results. In order to help developers understand API usages and write API client code more effectively, we have developed an API usage mining framework and its supporting tool called MAPO (for Mining API usages from Open source repositories). Given a query that describes a method, class, or package for an API, MAPO leverages the existing source code search engines to gather relevant source files and conducts data mining. The mining leads to a short list of frequent API usages for developers to inspect. MAPO currently consists of five components: a code search engine, a source code analyzer, a sequence preprocessor, a frequent sequence miner, and a frequent sequence post processor. We have examined the effectiveness of MAPO using a set of various queries. The preliminary results show that the framework is practical for providing informative and succinct API usage patterns.
Keywords: api; application programming interfaces; documentation; mining software repositories; pmd; program comprehension; search engine; sequences; source code; source code search engine

Math You Can't Use: Patents, Copyright, and Software - Klemens, B. (Brookings Institution Press, 2006)

Micro pattern evolution - Kim, Sunghun; Pan, Kai; Whitehead,Jr., E. James (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
When analyzing the evolution history of a software project, we wish to develop results that generalize across projects. One approach is to analyze design patterns, permitting characteristics of the evolution to be associated with patterns, instead of source code. Traditional design patterns are generally not amenable to reliable automatic extraction from source code, yet automation is crucial for scalable evolution analysis. Instead, we analyze “micro pattern” evolution; patterns whose abstraction level is closer to source code, and designed to be automatically extractable from Java source code or bytecode. We perform micro-pattern evolution analysis on three open source projects, ArgoUML, Columba, and jEdit to identify micro pattern frequencies, common kinds of pattern evolution, and bug-prone patterns. In all analyzed projects, we found that the micro patterns of Java classes do not change often. Common bug- prone pattern evolution kinds are ‘Pool → Pool’, ‘Implementor → NONE’, and ‘Sampler → Sampler’. Among all pattern evolution kinds,‘Box’,‘CompoundBox’, ‘Pool’, ‘CommonState’, and ‘Outline’ micro patterns have high bug rates, but they have low frequencies and a small number of changes. The pattern evolution kinds that are bug-prone are somewhat similar across projects. The bug-prone pattern evolution kinds of two different periods of the same project are almost identical.
Keywords: argouml; bugs; columba; design patterns; evolution; extraction; java; jedit; source code

The micro-dynamics of open source software development activity - David, Paul; Francesco Rullani (OSS2006: Open Source Systems (IFIP 2.13), 2006)
This study aims to isolate and identify the properties of FLOSS development insofar as these can be revealed by examining the ecology of SF.net. It characterizes the contrast between the many “lurkers” and a much smaller core of “entrepreneurial” developers who are responsible for launching new projects, and gives an interpretation of the function of platforms such as SF.net as sites that people with a propensity to start open source projects can use to recruit “laborers”. It describes the process underpinning the mobility of those who are recruited among the projects that are launched and provides insights on the evolution of developers’ level and mode of involvement in FLOSS production.

Mining additions of method calls in ArgoUML - Zimmermann, Thomas; Breu, Silvia; Lindig, Christian; Livshits, Benjamin (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
In this paper we refine the classical co-change to the addition of method calls. We use this concept to find usage patterns and to identify cross-cutting concerns for ArgoUML.
Keywords: argouml; change analysis; eclipse; function calls; mining challenge; msr challenge; pattern; source code; xelopes

Mining CVS Signals - Jean-Michel Dalle; L. Daudet; den Besten, Matthijs (1st Workshop on Public Data about Software Development (WoPDaSD 2006), 2006)

Mining eclipse for cross-cutting concerns - Breu, Silvia; Zimmermann, Thomas; Lindig, Christian (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
Software may contain functionality that does not align with its architecture. Such cross-cutting concerns do not exist from the beginning but emerge over time. By analysing where developers add code to a program, our history-based mining identifies cross-cutting concerns in a two-step process. First, we mine CVS archives for sets of methods where a call to a specific single method was added. In a second step, such simple cross-cutting concerns are combined to complex cross-cutting concerns. To compute these efficiently, we apply formal concept analysis—an algebraic theory. History-based mining scales well: we are the first to report aspects mined from an industrial-sized project like Eclipse. For example, we identified a locking concern that crosscuts 1284 methods.
Keywords: aspects; concept analysis; cvs; eclipse; source code

Mining email social networks - Christian Bird; Gourley, Alex; Devanbu, Prem; Gertz, Michael; Swaminathan, Anand (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
Communication & Co-ordination activities are central to large software projects, but are difficult to observe and study in traditional (closed-source, commercial) settings because of the prevalence of informal, direct communication modes. OSS projects, on the other hand, use the internet as the communication medium,and typically conduct discussions in an open, public manner. As a result, the email archives of OSS projects provide a useful trace of the communication and co-ordination activities of the participants. However, there are various challenges that must be addressed before this data can be effectively mined. Once this is done, we can construct social networks of email correspondents, and begin to address some interesting questions. These include questions relating to participation in the email; the social status of different types of OSS participants; the relationship of email activity and commit activity (in the CVS repositories) and the relationship of social status with commit activity. In this paper, we begin with a discussion of our infrastructure (including a novel use of Scientific Workflow software) and then discuss our approach to mining the email archives; and finally we present some preliminary results from our data analysis.
Keywords: communication; contributions; developers; email; email archives; mailing lists; open source; social networks

Mining email social networks in Postgres - Christian Bird; Gourley, Alex; Devanbu, Prem; Gertz, Michael; Swaminathan, Anand (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
Open Source Software (OSS) projects provide a unique opportunity to gather and analyze publicly available historical data. The Postgres SQL server, for example, has over seven years of recorded development and communication activity. We mined data from both the source code repository and the mailing list archives to examine the relationship between communication and development in Postgres. Along the way, we had to deal with the difficult challenge of resolving email aliases. We used a number of social network analysis measures and statistical techniques to analyze this data. We present our findings in this paper.
Keywords: developers; email; email archives; open source; postgresql; scm; social network analysis; social networks; source code; status

Mining large software compilations over time: another perspective of software evolution - Gregorio Robles; Jesus M. Gonzalez-Barahona; Martin Michlmayr; Amor, Juan Jose (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
With the success of libre (free, open source) software, a new type of software compilation has become increasingly common. Such compilations, often referred to as 'distributions', group hundreds, if not thousands, of software applications and libraries written by independent parties into an integrated system. Software compilations raise a number of questions that have not been targeted so far by software evolution, which usually focuses on the evolution of single applications. Undoubtedly, the challenges that software compilations face differ from those found in single software applications. Nevertheless, it can be assumed that both, the evolution of applications and that of software compilations, have similarities and dependencies.In this sense, we identify a dichotomy, common to that in economics, of software evolution in the small (micro-evolution) and in the large (macro-evolution). The goal of this paper is to study the evolution of a large software compilation, mining the publicly available repository of a well-known Linux distribution, Debian. We will therefore investigate changes related to hundreds of millions of lines of code over seven years. The aspects that will be covered in this paper are size (in terms of number of packages and of number of lines of code), use of programming languages, maintenance of packages and file sizes.
Keywords: debian; distributions; evolution; large software collections; lines of code; loc; metrics; mining software repositories; size; sloc; sloccount; software evolution; software integrators

Mining refactorings in ARGOUML - Weißgerber, Peter; Diehl, Stephan; Görg, Carsten (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
In this paper we combine the results of our refactoring reconstruc- tion technique with bug, mail and release information to perform process and bug analyses of the ARGOUML CVS archive.
Keywords: argouml; bug tracking; bugs; cvs; email; evolution; mining challenge; msr challenge; re-engineering; refactoring; release history

Mining sequences of changed-files from version histories - Kagdi, Huzefa; Yusuf, Shehnaaz; Maletic, Jonathan I. (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
Modern source-control systems, such as Subversion, preserve change-sets of files as atomic commits. However, the specific ordering information in which files were changed is typically not found in these source-code repositories. In this paper, a set of heuristics for grouping change-sets (i.e., log-entries) found in source-code repositories is presented. Given such groups of change-sets, sequences of files that frequently change together are uncovered. This approach not only gives the (unordered) sets of files but supplements them with (partial temporal) ordering information. The technique is demonstrated on a subset of KDE source-code repository. The results show that the approach is able to find sequences of changed-files.
Keywords: change; change history; change management; change sequences; heuristics; kde; mining software repositories; scm; sequences; source code

Mining software repositories with CVSgrab - Voinea, Lucian; Telea, Alexandru (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
Keywords: argouml; cvs; cvsgrab; evolution; mining challenge; msr challenge; postgresql; software visualization; source code; team; visualization

Mining version archives for co-changed lines - Zimmermann, Thomas; Kim, Sunghun; Zeller, Andreas; Whitehead,Jr., E. James (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
Files, classes, or methods have frequently been investigated in recent research on co-change. In this paper, we present a first study at the level of lines. To identify line changes across several versions, we define the annotation graph which captures how lines evolve over time. The annotation graph provides more fine-grained software evolution information such as life cycles of each line and related changes: "Whenever a developer changed line 1 of version.txt she also changed line 25 of Library.java."
Keywords: change; change analysis; change management; graph; lines of code; source code

Motivating Participation by Displaying the Value of Contribution - Al Mamunur Rashid; Kimberly Ling; Regina D Tassone; Paul Resnick; Robert Kraut; John Riedl (ACM SIGCHI Conference on Human Factors in Computing Systems, 2006)

Motivation, Governance, and the Viability of Hybrid Forms in Open Source Software Development - Shah, Sonali K. (Management Science, 2006)
Open source software projects rely on the voluntary efforts of thousands of software developers, yet we know little about why developers choose to participate in this collective development process. This paper inductively derives a framework for understanding participation from the perspective of the individual software developer based on data from two software communities with different governance structures. In both communities, a need for software-related improvements drives initial participation. The majority of participants leave the community once their needs are met, however, a small subset remains involved. For this set of developers, motives evolve over time and participation becomes a hobby. These hobbyists are critical to the long-term viability of the software code: They take on tasks that might otherwise go undone and work to maintain the simplicity and modularity of the code. Governance structures affect this evolution of motives. Implications for firms interested in implementing hybrid strategies designed to combine the advantages of open source software development with proprietary ownership and control are discussed.
Keywords: email; email archives; governance; INNOVATION; interview; mailing list; MOTIVATION; open source software development; Volunteers

Multi-Modal Modeling, Analysis and Validation of Open Source Software Development Processes - Walt Scacchi; Chris Jensen; Noll, J.; Elliott, M. (Intern. J. Internet Technology and Web Engineering, 2006)
Understanding the context, structure, activities, and content of software development processes found in practice has been and remains a challenging problem. In the world of free/open source software development, discovering and understanding what processes are used in particular projects is important in determining how they are similar to or different from those advocated by the software engineering community. Prior studies have revealed that development processes in F/OSSD projects are different in a number of ways. In this paper, we describe how a variety of modeling perspectives and techniques are used to elicit, analyze, and validate software development processes found in F/OSSD projects, with examples drawn from studies of the software requirements process found in the NetBeans.org project.
Keywords: empirical studies of software engineering; open source software development; process modeling; requirements processes; software process

Networks of Open Source Health Care Action - Staring, Knut; Titlestad, Ola (OSS2006: Open Source Systems (IFIP 2.13), 2006)
This paper reports on an effort to create a network of both developers and users of a public health information system. Through an analysis of capacity, recruitment, and power in the network, issues related to choice of technologies, global-local tensions, and parameters of institutional collaboration, we illustrate a number of challenges. Comparing OSS principles to a “Networks of Action” approach, conditions for learning in organizing training and development of software with participants from Africa, Asia, and Europe, as well as the involvement of advanced students in such efforts are discussed.

New Perspectives on Public Goods Production: Policy Implications of Open Source Software - Jyh-An Lee (2006)
This article reveals some empirical data regarding the trend of evolving open source software (OSS) policies globally. Additionally, this article investigates why so many governments are considering support of OSS development, and weighs the pros and cons of such policies. The ultimate conclusion is that when two systems are equally suitable, governments may reasonably choose OSS over proprietary software because software industry market failures may justify such support of OSS development. While governments considering supporting OSS are primarily concerned with significant switching costs and incompatibility problems, OSS is actually superior to proprietary software because it increases compatibility and consequently decreases switching costs in the long term. Further, OSS will not only help developing countries build their information technology capabilities, but will also promote competition in the software market.

An open framework for CVS repository querying, analysis and visualization - Voinea, Lucian; Telea, Alexandru (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
We present an open framework for visual mining of CVS software repositories. We address three aspects: data extraction, analysis and visualization. We first discuss the challenges of CVS data extraction and storage, and propose a flexible way to deal with CVS implementation inconsistencies. We next present a new technique to enrich the raw data with information about artifacts showing similar evolution. Finally, we propose a visualization backend and show its applicability on industry-size repositories.
Keywords: argouml; cvs; cvsgrab; evolution visualization; postgresql; software visualization

Open Source in Web-Based Applications - Ardagna, Claudio Agostino; Frati, Fulvio; Gabriele Gianini (International Journal of Information Technology and Web Engineering, 2006)
Business and recreational activities on the global communication infrastructure are increasingly based on the use of remote resources and services, and on the interaction between different, remotely located parties. In such a context, Single Sign-On technologies simplify the log-on process allowing automatic access to secondary domains through a unique log-on operation to the primary domain. In this article, we evaluate different Single Sign-On implementations focusing on the central role of Open Source in the development of Web-based systems. We outline requirements for Single Sign-On systems and evaluate four existing Open Source implementations in terms of degree of fulfilment of those requirements. Finally we compare those Open Source systems with respect to some specific Open Source community patterns.

Open Source in Web-based Periodicals - Baravalle, Andres; Chambers, Sarah (OSS2006: Open Source Systems (IFIP 2.13), 2006)
In this paper we aim to investigate the role of the media in the diffusion of Open Source, analysing three web-based periodicals from Italy, United Kingdom and USA. The influence of the media in our society is wide and we have to look to that direction if we want to seriously investigate the in-depth causes of the different trends. Nevertheless, our results show a picture that may not be familiar to many researchers of the field.

Open Source Software Development (OSSD) Based On Software Engineering - Zhu, Dengya; Potdar, Vidyasagar; Chang, Elizabeth (OSS2006: Open Source Systems (IFIP 2.13), 2006)
With the advent of Open Source Software (OSS) at the end of last century, many proponents believe that OSS is a new software development process and some even advocate OSS as a revolution for software engineering. The Cathedral and the Bazaar is a typical metaphor of the software development methodologies for the Closed Source Software (CSS) and the OSS. By comparing the phased (namely, requirement analysis, document design and system design, coding, testing and maintenance) software development methodology proposed by Software Engineering (SE), and by studying the management tools provided by SourceForge.net, we believe OSS development method not only follows the phased software development process, but also in return enriches the theory of SE.

Open Source Technical Support: A Look at Peer Help-Giving - Singh, V; Twidale, M.B; Rathi, D. (39th Annual Hawaii International Conference on System Sciences (HICSS'06)Proceedings of the 39th Annual Hawaii International Conference on System Sciences (HICSS'06), 2006)
We explore online technical support of open source software by a study of postings to discussion boards. Our results indicate that there are several types of detail that are required by the help-givers to be able to diagnose and remediate help-seekers’ difficulties. As a result help interactions may iterate somewhat inefficiently. These findings are compared with studies of telephone technical help lines for commercial software, and library reference interviews. By considering certain rather problematic interactions we can identify ways to improve the process.

Open Source & The Irish Software Industry? - Ed Sherwood-Smith (2006)
The open source software movement is a global phenomenon that is having a significant impact on the global software industry. It is changing the way in which software companies and people view the software development process. It is changing the way in which software companies capture value. It is commoditizing segments of the software market and is creating new business models and new ways of capturing value. It is lauded by some and vilified by others. It is often painted in a biblical light ??? David taking on Goliath. Yet, many of the Goliaths??? are also benefiting from this movement. This dissertation explores this - How can companies manage the impacts of the open source software movement to their advantage? This research examines the phenomenon in the context of the Irish Industry. Through a review of the existing literature this dissertation develops and exploratory framework for investigating different factors that might be influential in looking at how Indigenous Irish Software firms might manage the impacts of open source software movement. It weaves facets of different research areas together to produce this framework. The framework is then tested using several techniques including a qualitative survey. The dissertation includes several sections that apply the framework in order to analyze and develop profiles of several different firms. These profiles are then used to look at some of the different strategies and tactics available to firms. In many cases, examples are drawn from the global software industry to illustrate these approaches. The research concludes that there are factors that influence how a firm can manage the impact of the open source movement. It also builds on the initial framework to offer a more complete approach to understanding the factors that change the way in which firms manage the impacts of the open source software movement.

Opportunities and Challenges Applying Functional Data Analysis to the Study of Open Source Software Evolution - Stewart, Katherine J.; Darcy, David P.; Daniel, Sherae L. (Statistical Science, 2006)
This paper explores the application of functional data analysis (FDA) as a means to study the dynamics of software evolution in the open source context. Several challenges in analyzing the data from software projects are discussed, an approach to overcoming those challenges is described, and preliminary results from the analysis of a sample of open source software (OSS) projects are provided. The results demonstrate the utility of FDA for uncovering and categorizing multiple distinct patterns of evolution in the complexity of OSS projects. These results are promising in that they demonstrate some patterns in which the complexity of software decreased as the software grew in size, a particularly novel result. The paper reports preliminary explorations of factors that may be associated with decreasing complexity patterns in these projects. The paper concludes by describing several next steps for this research project as well as some questions for which more sophisticated analytical techniques may be needed.
Keywords: complexity; evolution; fda; java; lines of code; loc; release history; scm; size; sourceforge

Organization of Internet Standards - Gençer, Mehmet; Oba, Beyza; Özel, Bülent; Tunalıoğlu, V. (OSS2006: Open Source Systems (IFIP 2.13), 2006)
In this study we look at a body of standards documents in RFCs(Request For Comments) of IETF (Internet Engineering Task Force). The cross references between these documents form a network. Approaches from social network analysis are deployed to assess centrality of artifacts in this network and identify cohesive subgroups and levels of cohesion. Our results demonstrate major groups centered around key standard tracks, and application of network metrics reflect different levels of cohesion for these groups. As application of these techniques in such domains is unusual, possible uses in open source projects for strategizing are discussed.

The Organizational Adoption of Open Source Server Software by Belgian Organizations - Ven, Kris; Verelst, Jan (OSS2006: Open Source Systems (IFIP 2.13), 2006)
This study reports on five case studies in Belgian organizations that currently use open source server software. Respondents were asked about their motivation to use open source server software. Our results indicate that the lower cost, high reliability and availability of external support are the prime reasons why organizations use open source software. The often claimed advantage of open source software of having access to the source code was found relevant only for those organizations who perform development based on open source software. Some factors that were found relevant in previous studies (such as the support of standards) were however deemed less important by the organizations in our sample.

Participation in Free and Open Source Communities: An Empirical Study of Community Members’ Perceptions - Schofield, Andrew; Cooper, Grahame (OSS2006: Open Source Systems (IFIP 2.13), 2006)
Although the defining factors of Free and Open Source Software (FOSS) are generally seen as the availability and accessibility of the source code, it is what these facilitate that is perhaps of more significance. Source code availability allows the sharing of code, skills, knowledge, and effort, focused on a particular piece of software under development. The result of this is the FOSS community, which although often perceived as a single group, is actually many small groups, each bound by a common interest in a particular piece of software and using the Internet as a communication medium. Although there have been studies focusing on the motivation of FOSS developers to contribute to software, there has been little investigation into the motives, attitudes, and the culture within the communities as a whole. There is much more to most of these communities than software development. Many also have extensive support networks for the use of software, portals for research, and social facilities. This paper describes the results of an investigation into how FOSS community members perceive the communities that they belong to, their reasons for being in the community, and the manner in which they participate.
Keywords: Survey

Perceptions and Uptake of Open Source in Swedish Organisations - Lundell, Björn; Lings, Brian; Lindqvist, Edvin (OSS2006: Open Source Systems (IFIP 2.13), 2006)
There are many different ways in which Open Source ideas can be adopted by business, and influence the way in which companies do business. A number of different surveys have been conducted in different countries with the purpose of understanding the state of practice with respect to Open Source in companies. A number of different business models have been observed, ranging from the use of Open Source infrastructure products to basing a company’s entire business model on Open Source. In this paper we report on a study of the perceptions of Open Source and the uptake of open source products and development models in Swedish companies. We investigate this from the standpoint of stakeholders in those companies which have an expressed interest in Open Source, allowing a more in-depth analysis of the extent to which Open Source has influenced business thinking. From our analysis we find that uptake is much higher than reported in earlier studies, but is still concentrated in SMEs, consistent with the findings of previous studies. There is increased evidence of interest beyond the simple use of OS components at the (LAMP) infrastructure level. In particular, a significant proportion of the companies are in a symbiotic relationship with the OS community, supporting both through participation in existing projects and the release of new software under OS licences.

Predicting defect densities in source code files with decision tree learners - Knab, Patrick; Pinzger, Martin; Bernstein, Abraham (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
With the advent of open source software repositories the data available for defect prediction in source files increased tremendously. Although traditional statistics turned out to derive reasonable results the sheer amount of data and the problem context of defect prediction demand sophisticated analysis such as provided by current data mining and machine learning techniques.In this work we focus on defect density prediction and present an approach that applies a decision tree learner on evolution data extracted from the Mozilla open source web browser project. The evolution data includes different source code, modification, and defect measures computed from seven recent Mozilla releases. Among the modification measures we also take into account the change coupling, a measure for the number of change-dependencies between source files. The main reason for choosing decision tree learners, instead of for example neural nets, was the goal of finding underlying rules which can be easily interpreted by humans. To find these rules, we set up a number of experiments to test common hypotheses regarding defects in software entities. Our experiments showed, that a simple tree learner can produce good results with various sets of input data.
Keywords: change analysis; data mining; decision tree learner; defect density; defect prediction; mozilla; prediction; release history; scm; source code; version control

A preliminary examination of code review processes in open source projects - Peter C. Rigby; Daniel M. German (2006)
In this paper, we provide preliminary answers to the following questions regarding OSS peer review or inspection. What is the patch process and review process used by the projects? What types of review does a the project use? Why are patches rejected? What percentage of patches are rejected? Who performs the review? Are the top developers also the top reviewers? When are reviews performed? What is the frequency of review? How long do reviews take to perform? How does the patch size affect the review? How does merit-based trust among actors affect the review? Are more trusted individuals reviewed less often? How much feedback is provided in the review? What kinds of non-source code patches are reviewed? How does the kind of patch affect the review? What affect does reviewing have on other elements of the patch process? What is the relationship between reviewing and testing? The first two questions are answered in a qualitative manner for GCC, Linux, Mozilla, and Apache. The remaining questions are answered for the Apache project. The most striking similarities among projects is there use of a pre-commit review and requests for small, complete, independent patches. The Apache project also uses a post-commit review of trusted members. Reviews in the Apache project occur very frequently and usually have a review interval of hours. A small core group of reviewers conduct over 80% of reviews for Apache; however, the number of and actual individuals fluctuates over the 9 years of data we examine.

Producing and Interpreting Debug Texts - Østerlie, Thomas (OSS2006: Open Source Systems (IFIP 2.13), 2006)
This paper presents preliminary findings from an ethnographic study of distributed, parallel debugging in an open source software (OSS) community. Focusing on the OSS developers’ daily activities, I propose the concept of making software debuggable. In so doing, I see a somewhat different story than common narratives of debugging in current OSS research, which describes distributed, parallel debugging as a set of highly cohesive tasks within loosely couple groups. I find that parallel, distributed debugging is rather a closely coupled collective process of producing and interpreting debug texts with high cohesion between the activities of reporting, finding, and understanding bugs.

Regurgitate: Using GIT For F/LOSS Data Collection - Bart Massey; Keith Packard (1st Workshop on Public Data about Software Development (WoPDaSD 2006), 2006)
We have created a new tool, regurgitate, for importing CVS repositories into the GIT source code management system. Important features of GIT include great expressiveness in capturing relationships between revisions and across files as well as extremely high-speed processing. These features make GIT an ideal platform for gathering detailed longitudinal metrics for open source projects. The availability of regurgitate facilitates using GIT as an analysis tool for that majority of open source projects that keep their repositories in CVS. In particular, GIT is fast enough that it is practical to replay the entire development history of a project commit-at-a-time, collecting metrics at each step. We demonstrate this process for a simple metric and a collection of benchmark F/LOSS repositories.
Keywords: cvs; cvsanaly; git; history; promise; regurgitate; scm

Retrieving Open Source Software Licenses - Tuunanen, Timo; Koskinen, Jussi; Kärkkäinen, Tommi (OSS2006: Open Source Systems (IFIP 2.13), 2006)
Open Source Software maintenance and reuse require identifying and comprehending the applied software licenses. This paper first characterizes software maintenance, and open source software (OSS) reuse which are particularly relevant in this context. The information needs of maintainers and reusers can be supported by reverse engineering tools at different information retrieval levels. The paper presents an automated license retrieval approach called ASLA. User needs, system architecture, tool features, and tool evaluation are presented. The implemented tool features support identifying source file dependencies and licenses in source files, and adding new license templates for identifying licenses. The tool is evaluated against another tool for license information extraction. ASLA requires the source code as available input but is otherwise not limited to OSS. It supports the same programming languages as GCC. License identification coverage is good and the tool is extendable.
Keywords: gaim; license; license analysis; maintenance; mozilla; reuse

Reusable Parser Generation from Open Source Compilers - Maeda, Kazuaki (OSS2006: Open Source Systems (IFIP 2.13), 2006)
Without Abstract

A Robust Open Source Exchange for Open Source Software Development - Basu, Amit (OSS2006: Open Source Systems (IFIP 2.13), 2006)
This paper addresses the development of mechanisms for the creation of OSSD exchanges that could be used by developers across any geographical range, as long as all the developers can interact via some open network infrastructure such as the Internet. The structure of these exchanges can range from public repositories such as Sourceforge.net to intra-organizational forums for software development within an enterprise. We examine in particular the structure of an exchange model based on protocols for a robust online marketplace.

The role of mental models in FLOSS development work practices - Kevin Crowston; Barbara Scozzi (OSS2006: Open Source Systems (IFIP 2.13), 2006)
Shared understandings are important for software development as they guide to effective individual contributions to, and coordination of, the software development process. In this paper, we present the theoretical background and research design for a proposed study on shared mental models within Free/Libre Open Source Software (FLOSS) development teams. In particular, we plan to perform case studies on several projects and to use cognitive maps analysis to represent and compare the mental models of the involved members so as to gauge the degree of common knowledge and the development of a collective mind as well as to better understand the reasons that underlie team members actions and the way common mental models, if any, arise.

Scope and Timing of Deployment: Moderators of Organizational Adoption of the Linux Server Platform. - Joel West; Dedrick, Jason (International Journal of IT Standards Research, 2006)
Market selection of product compatibility standards has long been explained through aggregate positive-feedback theoretical models of economic utility. Explaining aggregate patterns of organizational standards adoption requires two additional steps — not only differences between organizations, but also differences within organizations. Here we present a qualitative study of how organizations do (or do not) adopt a new computer server platform standard, namely Linux using PC-compatible hardware. While discussions of Linux typically focus on its open source origins, our respondents were primarily interested in low price. Despite this relative advantage in price, incumbent standards enjoyed other advantages identified by prior theory, namely network effects and switching costs. We show when, how and why such incumbent advantages are overcome by a new standard. We find that Linux adoption within organizations began for uses with a comparatively limited scope of deployment, thus minimizing network effect and switching costs disadvantages. We identify four attributes of information systems that potentially limit the scope of deployment: few links of the system to organizational processes, special-purpose computer systems, new uses and replacement of obsolete systems. We also identify an organizational level variable — internal standardization — which increases scope of deployment and thus the attractiveness of the incumbent standard.

Self-Organization Patterns in Wasp and Open Source Communities - Valverde, S.; Theraulaz, G.; Gautrais, J.; Fourcassie, V.; Sole, R.V. (IEEE Intelligent Systems, 2006)
In this paper, we conducted a comparative study of how social organization takes place in a wasp colony and OSS developer communities. Both these systems display similar global organization patterns, such as hierarchies and clear labor divisions. As our analysis shows, both systems also define interacting agent networks with similar common features that reflect limited information sharing among agents. As far as we know, this is the first research study analyzing the patterns and functional significance of these systems' weighted-interaction networks. By illuminating the extent to which self-organization is responsible for patterns such as hierarchical structure, we can gain insight into the origins of organization in OSS communities.
Keywords: agents; decentralization; developers; email; email archives; flossmole; hierarchy; labor division; organization; self-organizing teams; social network analysis; social networks; sourceforge; teams; wasps

Skills, Division of Labor and Performance in Collective Inventions. Evidence from the Open Source Software - Paola Giuri; Matteo Ploner; Francesco Rullani; Salvatore Torrisi (2006)
This paper investigates the role of skills and the division of labor among participants in collective inventions. Our analysis draws on a large sample of projects registered at Sourceforge.net, the world's largest incubator of open source software activity. We test the hypothesis that the level of skills of participants and their skill variety are important for project performance. Skill heterogeneity across participants is in line with two fundamental organizational features of the open source development model: team work and modular design. We also explore the hypothesis whether the level of modularization of project activities is an important predictor of performance. Our econometric estimations show that both skill level and skill heterogeneity positively affect projects' survival and performances. However, the impact of skill diversity is non linear. Design modularity is also positively associated with the performance of the project.

Social dynamics of free and open source team communications - James Howison; Inoue, K.; Kevin Crowston (Proceedings of the IFIP 2nd International Conference on Open Source Software, Lake Como, Italy, 2006)

Social dynamics of free and open source team communications - Howison, James; Inoue, Keisuke; Kevin Crowston (OSS2006: Open Source Systems (IFIP 2.13), 2006)
This paper furthers inquiry into the social structure of free and open source software (FLOSS) teams by undertaking social network analysis across time. Contrary to expectations, we confirmed earlier findings of a wide distribution of centralizations even when examining the networks over time. The paper also provides empirical evidence that while change at the center of FLOSS projects is relatively uncommon, participation across the project communities is highly skewed, with many participants appearing for only one period. Surprisingly, large project teams are not more likely to undergo change at their centers.
Keywords: bug fixing; bug reports; bug tracker; bug tracking; bugs; communications; Dynamic social networks; FLOSS teams; Human Factors; social network analysis; software development; sourceforge

Software Patents and Open Source Software in the European Union: Evidences of a Trade-Off? - Rentocchini, Francesco; De Prato, Giuditta (OSS2006: Open Source Systems (IFIP 2.13), 2006)
The present work aims at giving an account of the patenting behaviour in the software sector, focusing on the European Union and pointing out issues regarding a trade-off which would support a policy attitude in favour of a wider diffusion of the Open Source model.

Strategic Interaction and Knowledge Sharing in the KDE Developer Mailing List - Kuk, George (Management Science, 2006)
In stark contrast with the fully participative "bazaar" imagery of open source software (OSS) development, some recent empirical research has pointed out that much of the OSS development is carried out by a small percentage of developers. This raises serious concerns that concentration of development effort on a few will limit knowledge sharing and underutilize the available resources. Using the notion of strategic interaction, this paper argues that individual developers often interact strategically with other highly resourceful developers by forming a smaller but better organized structure to intensify the types of epistemic interactions that matter most to the OSS development. A general framework of strategic interaction including participation inequality, conversational interactivity, and cross-thread connectivity is proposed to examine its impact on knowledge sharing, and validated using 128 discussion threads from the K Desktop Environment (KDE) developer mailing list. The findings indicate that strategic interaction has expanded knowledge sharing but with the caveat that extreme concentration of development could have an opposite effect. For researchers, this study dovetails the incentive logic by proposing and validating the strategic aspects of OSS participation to better understand the collective dynamics underpinning OSS development. Practitioners can use this approach to evaluate and better support existing knowledge-sharing initiatives.
Keywords: developers; email; email archives; kde; knowledge collaboration; knowledge sharing; mailing list

A structurational perspective on leadership in technology-supported self-organizing small groups - Kevin Crowston; Robert Heckman; Nora Misiolek (Syracuse University School of Information Studies, 2006)
In this conceptual paper, we present a structuration-based theory of leadership behaviours in virtual teams, that is to say, in self-organizing technology-supported small groups such as Free/Libre Open Source Software development teams. Such teams are often composed of members of relatively equal status or who are so disparate in background that formal organizational status seems irrelevant, reducing the usual leadership cues provided by organizational status and title. Building on behavioural leadership theory and structuration theory, we present a two-order theory of leadership. It describes four classes of first-order leadership behaviours (task coordination, substantive task contribution, group maintenance, and boundary spanning) and defines second-order leadership as behaviour that influences changes in the structure that guides group action. Specifically, we suggest that second-order leadership behaviours are those that build structures of signification in the form of interpretive schema, structures of domination in the form of role structures and structures of legitimation in the form of rules and norms. We argue that second-order leadership is enabled by first-order leadership, is therefore action embedded, and is grounded in processes that define the social identity of the group. We propose that effective teams will exhibit a paradoxical combination of shared, distributed first-order leadership complemented by strong, concentrated, and centralized second-order leadership. We conclude by suggesting future research that might be conducted to test and further elaborate our theory.

A study of the contributors of PostgreSQL - Daniel M. German (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
This report describes some characteristics of the development team of PostgreSQL that were uncovered by analyzing the history of its software artifacts as recorded by the project's CVS repository.
Keywords: contributions; contributors; cvs; developers; mining challenge; mining software repositories; msr challenge; patches; postgresql; revision history; roles; software evolution; source code; team

A study on the introduction of Open Source Software in the Public Administration - Rossi, Bruno; Russo, Barbara; Succi, Giancarlo (OSS2006: Open Source Systems (IFIP 2.13), 2006)
This paper reports about a study on the introduction of Open Source Software (OSS) in a Public Administration located in Europe. The Public Administration examined has introduced OSS as a means to save on the license costs and to have a larger space for customisation purposes. The adoption of new software may have an impact on the employees’ productivity that need to be addressed. In this article, we compare the usage of OpenOffice.org and Microsoft Office. Data about the usual office activities performed by the users participating to the experimentation have been collected by means of an automated non-invasive data collection tool. The result of this study reports a similar usage pattern of both suites in terms of workload, but a different approach in using functionalities provided by each software. A further analysis on the life cycles of documents elaborated with the office suites seems to validate the similarities among the software solutions examined.

tagging, community, vocabulary, evolution - Shilad Sen; Shyong K. Lam; Dan Cosley; Al Mamunur Rashid; Dan Frankowski; Franklin Harper; Jeremy Osterhouse; John Riedl (Computer Supported Cooperative Work, 2006)

A tool for the measurement, storage, and pre-elaboration of data supporting the release of public datasets (1st Workshop on Public Data about Software Development (WoPDaSD 2006), 2006)
The big number of projects producing open source software provides researches with the possibility to measure software artefacts, thus producing a huge amount of data that are available for analysis. In order to be efficient and reliable, the process of data retrieval and analysis needs to be adequately supported by tools. In particular, measurement tools should guarantee that a large amount of artefacts are measured in a coherent and efficient way. They should also guarantee that the delivered measures have a well specified structure and meaning, which should be agreed upon by the community of researchers interested in analysing the data. A problem that such tools have to face is that all the elements involved are highly variable: the data source can be available in different versions; the measures to be carried out can be defined in (often only slightly) different ways; it is usually different the output required by different types of analysis. Another non trivial problem is that measured data have to be stored persistently in a way that lets the user not only retrieve the data, but also the meta-data describing the measurement themselves. In this paper we describe a tool that addresses the requirements described above, and present a first implementation that satisfies several of such requirements.

A tool to support the introduction of GNU/Linux desktop system in a professional environment - Di Cerbo, Francesco; Favara, Daniele; Scotto, Marco; Sillitti, Alberto; Succi, Giancarlo; Vernazza, Tullio (OSS2006: Open Source Systems (IFIP 2.13), 2006)
The introduction of a GNU/Linux-based desktop system in a large company is often problematic, in terms of technical issues but especially for employees’ training costs. Mainly, these obstacles are represented by different hardware configurations that might require several ad-hoc activities to adapt a standard release to the specific environment, including company’s application profile. On the other hand, GNU/Linux live distributions provide to the users’ community new and interesting capabilities, as self-configuration and better usability, but loosing compatibility with original distributions, that is unaffordable in professionals scenarios. DSS (Debased Scripts Set) is an answer to both questions. It is a live distribution that includes an unmodified Debian-based Linux release and a modular-designed file system.

A Topological Analysis of the Open Souce Software Development Community - Jin Xu; Gao, Yongqin; Christley, S.; Madey, G. (Proceedings of the 38th Annual Hawaii International Conference on System Sciences, 2006)
The fast growth of OSS has increased the interest in studying the composition of the OSS community and its collaboration mechanisms. Moreover, the success of a project may be related to the underlying social structure of the OSS development community. In this paper, we perform a quantitative analysis of Open Source Software developers by studying the entire development community at SourceForge [26]. Statistics and social network properties are explored to find collaborations and the effects of different members in the OSS development community. Small world phenomenon and scale free behaviors are found in the SourceForge development network. These topological properties may potentially explain the success and efficiency of OSS development practices. We also infer from our analysis that weakly associated but contributing co-developers and active users may be an important factor in OSS development.
Keywords: contributors; developers; roles; social network analysis; social networks; sourceforge; srda; users

Towards an Ontology for Open Source Software Development - Simmons, Gregory; Dillon, Tharam (OSS2006: Open Source Systems (IFIP 2.13), 2006)
Software development is a knowledge intensive process and the information generated in open source software development projects is typically housed in a central Internet repository. Open source repositories typically contains vast amounts of information, much of it unstructured, meaning that even if a question has previously been discussed and dealt with it is not a trivial task to locate it. This can lead to rework and confusion amongst developers and possibly deter new developers from getting involved in the project in the first place. This paper will present the case for an open source software development ontology. Such an ontology would enable better categorization of information and the development of sophisticated knowledge portals in order to better organize community knowledge and increase efficiency in the open source development process.

Understanding Free/Open Source Software Development Processes - Walt Scacchi; Feller, Joseph; Fitzgerald, Brian; Hissam, Scott; Lakhani, Karim (Software Process--Improvement and Practice, 2006)

Understanding Free/Open Source Software Evolution - Walt Scacchi (Software Evolution and Feedback: Theory and Practice, 2006)

Understanding the Motivations, Participation, and Performance of Open Source Software Developers: A Longitudinal Study of the Apache Projects - Roberts, Jeffrey A.; Il-Horn Hann; Slaughter, Sandra A. (Management Science, 2006)
Understanding what motivates participation is a central theme in the research on open source software (OSS) development. Our study contributes by revealing how the different motivations of OSS developers are interrelated, how these motivations influence participation leading to performance, and how past performance influences subsequent motivations. Drawing on theories of intrinsic and extrinsic motivation, we develop a theoretical model relating the motivations, participation, and performance of OSS developers. We evaluate our model using survey and archival data collected from a longitudinal field study of software developers in the Apache projects. Our results reveal several important findings. First, we find that developers’ motivations are not independent but rather are related in complex ways. Being paid to contribute to Apache projects is positively related to developers’ status motivations but negatively related to their use-value motivations. Perhaps surprisingly, we find no evidence of diminished intrinsic motivation in the presence of extrinsic motivations; rather, status motivations enhance intrinsic motivations. Second, we find that different motivations have an impact on participation in different ways. Developers’ paid participation and status motivations lead to above-average contribution levels, but use-value motivations lead to below-average contribution levels, and intrinsic motivations do not significantly impact average contribution levels. Third, we find that developers’ contribution levels positively impact their performance rankings. Finally, our results suggest that past-performance rankings enhance developers’ subsequent status motivations.
Keywords: apache; change logs; contributions; email; email archives; extrinsic motivation; intrinsic motivation; mailing lists; MOTIVATION; open source software; participation; software development performance; source code; status; Survey

Usability processes in open source projects - David M Nichols; Michael B Twidale (Software Process: Improvement and Practice, 2006)
We explore how some open source projects address issues of usability. We describe the mechanisms, techniques and technology used by open source communities to design and refine the interfaces to their programs. In particular we consider how these developers cope with their distributed community, lack of domain expertise, limited resources and separation from their users. We also discuss how bug reporting and discussion systems can be improved to better support bug reporters and open source developers.

User Choices and Regret: Understanding Users' Decision Process bout Consensually Acquired Spyware - N. Good; J. Grossklags; Konstan, J.A.; D. Mulligan; A. Perzanowski; D. Thaw (I/S: A Journal of Law and Policy for the Information Society, 2006)

Using evolutionary annotations from change logs to enhance program comprehension - Daniel M. German; Peter C. Rigby; Storey, Margaret-Anne (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
Evolutionary annotations are descriptions of how source code evolves over time. Typical source comments, given their static nature, are usually inadequate for describing how a program has evolved over time; instead, source code comments are typically a description of what a program currently does. We propose the use of evolutionary annotations as a way of describing the rationale behind changes applied to a given program (for example "These lines were added to ..."). Evolutionary annotations can assist a software developer in the understanding of how a given portion of source code works by showing him how the source has evolved into its current form.In this paper we describe a method to automatically create evolutionary annotations from change logs, defect tracking systems and mailing lists. We describe the design of a prototype for Eclipse that can filter and present these annotations alongside their corresponding source code and in workbench views. We use Apache as a test case to demonstrate the feasibility of this approach.
Keywords: annotations; apache; bug tracking; change history; eclipse; evolutionary; log files; mailing lists; mining software repositories; software evolution; version control

Using Intelligent Task Routing and Contribution Review to Help Communities Build Artifacts of Lasting Value - Cosley, D.; D. Frankowski; Terveen, L.; Riedl, J. (ACM SIGCHI Conference on Human Factors in Computing Systems, 2006)

Using software birthmarks to identify similar classes and major functionalities - Kakimoto, Takeshi; Monden, Akito; Kamei, Yasutaka; Tamada, Haruaki; Tsunoda, Masateru; Matsumoto, Ken-ichi (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
Keywords: argouml; class; file; mining challenge; msr challenge; multi-dimensional scaling; similarity; software birthmark; source code

On the Weickian Model in the Context of Open Source Software Development: Some Preliminary Insights - Iannacci, Federico (OSS2006: Open Source Systems (IFIP 2.13), 2006)
Despite being regarded as a path-breaking model of organising, Weick’s Enactment-Selection-Retention (ESR) model has been labelled too abstract a model find any practical applications. This paper attempts to show that exploration-oriented open source projects represent valuable case studies where Weick’s ESR model can be applied. By taking the Linux case study as a case in point, it is argued that a qualitative analysis of micro interactions (i.e. double interacts) might reveal broad organising patterns. Preliminary implications in terms of coordination and knowledge making processes are discussed in the final section.
Keywords: case study; linux

Where is bug resolution knowledge stored? - Canfora, Gerardo; Cerulo, Luigi (Proceedings of the 2006 international workshop on Mining software repositories, 2006)
ArgoUML uses both CVS and Bugzilla to keep track of bug-fixing activities since 1998. A common practice is to reference source code changes resolving a bug stored in Bugzilla by inserting the id number of the bug in the CVS commit notes. This relationship reveals useful to predict code entities impacted by a new bug report.In this paper we analyze ArgoUML software repositories with a tool, we have implemented, showing what are Bugzilla fields that better predict such impact relationship, that is where knowledge about bug resolution is stored.
Keywords: argouml; bugs; bugzilla; cvs; impact analysis; mining challenge; mining software repositories; msr challenge; source code

Who should fix this bug? - Anvik, John; Hiew, Lyndon; Murphy, Gail C. (Proceedings of the 28th international conference on Software engineering, 2006)
Open source development projects typically support an open bug repository to which both developers and users can report bugs. The reports that appear in this repository must be triaged to determine if the report is one which requires attention and if it is, which developer will be assigned the responsibility of resolving the report. Large open source developments are burdened by the rate at which new bug reports appear in the bug repository. In this paper, we present a semi-automated approach intended to ease one part of this process, the assignment of reports to a developer. Our approach applies a machine learning algorithm to the open bug repository to learn the kinds of reports each developer resolves. When a new report arrives, the classifier produced by the machine learning technique suggests a small number of developers suitable to resolve the report. With this approach, we have reached precision levels of 57% and 64% on the Eclipse and Firefox development projects respectively. We have also applied our approach to the gcc open source development with less positive results. We describe the conditions under which the approach is applicable and also report on the lessons we learned about applying machine learning to repositories used in open source development.
Keywords: bug fixing; bug report; bug report assignment; bug triage; eclipse; Firefox; gcc; issue tracking; machine learning; problem tracking

Wikifying your interface: Facilitating Community-Based Interface Translation - Jones, M.C.; Rathi, D.; Twidale, M.B (Proceedings of the 6th ACM conference on Designing Interactive systems - DIS '06, 2006)
We explore the application of a wiki-based technology and style of interaction to enabling the incremental translation of a collaborative application into a number of different languages, including variant English language interfaces better suited to the needs of particular user communities. The development work allows us to explore in more detail the design space of functionality and interfaces relating to tailoring, customization, personalization and localization, and the challenges of designing to support ongoing incremental contributions by members of different use communities.

Accelerating cross-project knowledge collaboration using collaborative filtering and social networks - Ohira, Masao; Ohsugi, Naoki; Ohoka, Tetsuya; Matsumoto, Ken-ichi (Proceedings of the 2005 international workshop on Mining software repositories, 2005)
Vast numbers of free/open source software (F/OSS) development projects use hosting sites such as Java.net and SourceForge.net. These sites provide each project with a variety of software repositories (e.g. repositories for source code sharing, bug tracking, discussions, etc.) as a media for communication and collaboration. They tend to focus on supporting rich collaboration among members in each project. However, a majority of hosted projects are relatively small projects consisting of few developers and often need more resources for solving problems. In order to support cross-project knowledge collaboration in F/OSS development, we have been developing tools to collect data of projects and developers at SourceForge, and to visualize the relationship among them using the techniques of collaborative filtering and social networks. The tools help a developer identify “who should I ask?” and “what can I ask?” and so on. In this paper, we report a case study of applying the tools to F/OSS projects data collected from SourceForge and how effective the tools can be used for helping cross-project knowledge collaboration.
Keywords: collaborative filtering; developers; knowledge collaboration; projects; social networks; sourceforge; visualization tool

Analysing the technological history of the Open Source Phenomenon: Stories from the Free Software Evolution - Lorenzo Benussi (2005)
The Free Libre Open Source Software represents an outstanding example of open development model of technological knowledge. It has been studied in several researches that produced valuable illustrations of the way it works. Our understanding of its principal features is growing exponentially and an entire new literature on open source has been created. However there appears to be an important gap in the literature: the origin of the phenomenon. The paper attempts to tackle this issue by analyzing the long-term technological history of Free Open Source Software; the main research questions at stake are: is the phenomenon completely new? and if it is not totally new, where it comes form? and, more generally, how open source software developed over time? As a consequence the present work focuses primarily on the analysis of the fee/open source software history of technological change over a period of almost sixty years. I adopted a multidisciplinary approach to analyse the network of relations emerging between inventions and technological innovations, as well as economic determinants and intellectual property rights regimes throughout the period considered. Thus, I attempt to investigate the origins of the phenomenon as a way of understanding its evolution.

An Analysis of COSPA - A Consortium for Open Source in the Public Administration - Morgan, Lorraine (OSS2005: Open Source Systems, 2005)
This paper reflects on a two-year EU funded specific research targeted project that officially began in January 2004 entitled COSPA, a Consortium for studying, evaluating and supporting the introduction of Open Source Software and Open Data Standards in the Public Administration. COSPA focuses on office automation and desktop system software and aims at rigorously measuring the effort, costs and benefits of a transition to Open Source. The project involves 15 European Universities and Public Administrations from Italy, Hungary, Ireland, Denmark, UK, Belgium and about sixty observers, including the University of Alberto (Canada), Victoria University of Wellington (New Zealand) and the United Nations Educational Scientific and Cultural Organisation (UNESCO).

Analysis of signature change patterns - Kim, Sunghun; Whitehead,Jr., E. James; Bevan, Jennifer (Proceedings of the 2005 international workshop on Mining software repositories, 2005)
Software continually changes due to performance improvements, new requirements, bug fixes, and adaptation to a changing operational environment. Common changes include modifications to data definitions, control flow, method/function signatures, and class/file relationships. Signature changes are notable because they require changes at all sites calling the modified function, and hence as a class they have more impact than other change kinds.We performed signature change analysis over software project histories to reveal multiple properties of signature changes, including their kind, frequency, and evolution patterns. These signature properties can be used to alleviate the impact of signature changes. In this paper we introduce a taxonomy of signature change kinds to categorize observed changes. We report multiple properties of signature changes based on an analysis of eight prominent open source projects including the Apache HTTP server, GCC, and Linux 2.5 kernel.
Keywords: apache; gcc; kernel; linux; signature change; signature change patterns; software evolution; software evolution path; soure code

Anarchy and Source Code - What does the Free Software Movement have to do with Anarchism? - Christian Imhorst (2005)
What does the hacker ethic have to do with anarchism? Why does Richard Stallman, an outstanding personality of the free software movement, described himself as an anarchist? We should not imagine the anarchists of the Free Software Movement to be like the cartoon image: A scruffy looking lunatic, with a crazy glint in his eyes and bristling with weapons. Instead of chaos, Stallman postulates a new form of order for the intellectual property in the terms of the hacker ethic - the access to knowledge should be free, decentralized, anti-bureaucratic and anti-authoritarian.

Are All Open Source Projects Created Equal? Understanding the Sustainability of Open Source Software Development Model - Long, J.; Yuan, M.J. (AMCIS 2005 Proceedings, 2005)
A very intriguing question in Open Source software (OSS) development is: why there are only a few open source projects succeed, while the majority of projects never do. In this research, we examine the factors that may influence the performance of OSS projects. We particularly focus on the OSS’s core developers’ role in the project’s success. Extant research has yet to distinguish core developers and non-core developers from the community at large. The different roles of the core developers and non-core developers in OSS projects’ success still remain unclear. Our research contributes to the literature by separating the core developers from the development forces in general and empirically examining the core developers’ importance. Drawing the evidences from our extensive dataset of 300 open source projects, we demonstrated that core developers’ leadership and project advocation are crucial in determining the fate of the OSS projects. Our research could provide better understanding of OSS sustainability. It could also give practical advice to the OSS community on how to make the project successful.
Keywords: contributors; core; developers; downloads; metadata; project success; sourceforge

Assessing the Role of Open Source Software in the European Secondary Software Sector: A Voice from Industry - Ågerfalk, Pär J; Deverell, Andrea; Fitzgerald, Brian; Morgan, Lorraine (OSS2005: Open Source Systems, 2005)
This paper addresses the open source software (OSS) phenomenon from an industry perspective and reveals a number of complexities surrounding the role of OSS in the secondary software sector. It presents the research results of an international workshop which was hosted with the explicit intention of extracting the voice of key industrial stakeholders. The data was gathered and analysed using a qualitative approach which revealed the key strengths and weaknesses of OSS from an industrial perspective. This formed the foundations for developing a framework describing the emerging commercial incarnation of OSS (we refer to this as Open Source Software, Inc.) The paper concludes that the European secondary software sector recognise the benefits of leveraging OSS but are aware of key issues pertinent to such an end.

Brazil adopts open-source software - Kingstone, Steve (BBC News, 2005)

The calm before the storm? Legal challenges to open source licences - Gonzalez, Andres Guadamuz (OSS2005: Open Source Systems, 2005)
This paper will concentrate on presenting a legal analysis of two of the main challenges to open source software: SCO’s litigation and software patents. The paper discusses the validity of such challenges, their possible impact to the future of open source software, and the possible legal defences used against them.