@conference {1304, title = {Entering the circle of trust}, booktitle = {Proceeding of the 8th working conference on Mining software repositories - MSR {\textquoteright}11}, year = {2011}, note = {"we started by analyzing 219 projects" }, month = {05/2011}, pages = {133-142}, publisher = {ACM Press}, organization = {ACM Press}, address = {New York, New York, USA}, abstract = {The success of an open-source project depends to a large degree on the proactive and constructive participation by the developer community. An important role that developers play in a project is that of a code committer. However, code-commit privilege is typically restricted to the core group of a project. In this paper, we study the phenomenon of the induction of external developers as code committers. The trustworthiness of an external developer is one of the key factors that determines the granting of commit privileges. Therefore, we formulate different hypotheses to explain how the trust is established in practice. To investigate our hypotheses, we developed an automated approach based on mining code repositories and bug-tracking systems. We implemented the approach and performed an empirical study, using the Eclipse projects, to test the hypotheses. Our results indicate that, most frequently, developers establish trust and credibility in a project by contributing to the project in a non-committer role. Moreover, the employing organization of a developer is another factor--although a less significant one--that influences trust.}, keywords = {bug tracking, bug tracking system, commits, committers, core, developers, eclipse, trust}, isbn = {9781450305747}, doi = {10.1145/1985441.1985462}, author = {Mani, Senthil and Sinha, Saurabh and Sinha, Vibha Singhal} } @conference {1256, title = {Analyzing Leadership Dynamics in Distributed Group Communication}, booktitle = {2010 43rd Hawaii International Conference on System Sciences (HICSS 2010)}, year = {2010}, note = {"Our analysis examines the communication patterns in two FLOSS development projects, Fire and Gaim" "These data were imported into a database to allow automated analysis. The Fire data set includes about 1,800 events in the user email list, 7,800 messages in the developer venues, and 1,300 events in the combined trackers, spanning a period of 54 months. The significantly larger Gaim data set included over 41,000 events in the user forum, over 30,000 events in the developer venues, and about 20,000 events in the trackers, generated over 78 months." "The dynamic network analysis was performed using a scientific workflow tool, Taverna Workbench"}, pages = {1 - 10}, publisher = {IEEE}, organization = {IEEE}, address = {Honolulu, Hawaii, USA}, abstract = {We apply social network analysis (SNA) to examine the dynamics of leadership in distributed groups, specifically Free/Libre Open Source Software development projects, and its relation to group performance. Based on prior work on leadership in distributed groups, we identify leaders with those who make the highest level of contribution to the group and assess the degree of leadership by measuring centralization of communications. We compare the dynamics of leadership in two FLOSS projects, one more and one less effective. We find that in both projects, centralization was higher in developer-oriented communications venues than in user-oriented venues, suggesting higher degrees of leadership in developer venues. However, we do not find a consistent relation between centralization and effectiveness. We suggest that SNA can instead be useful for identifying interesting periods in the history of the project, e.g., periods where the leadership of the project is in transition.}, keywords = {core, DYNAMICS, email, email archives, fire, flossmole, gaim, leadership, mailing list, project success, social network analysis, srda}, isbn = {978-1-4244-5509-6}, doi = {10.1109/HICSS.2010.62}, attachments = {https://flosshub.org/sites/flosshub.org/files/07-06-02.pdf}, author = {Kevin Crowston and Andrea Wiggins and Howison, James} } @conference {941, title = {Evolution of the core team of developers in libre software projects}, booktitle = {2009 6th IEEE International Working Conference on Mining Software Repositories (MSR)2009 6th IEEE International Working Conference on Mining Software Repositories}, year = {2009}, pages = {167 - 170}, publisher = {IEEE}, organization = {IEEE}, address = {Vancouver, BC, Canada}, abstract = {In many libre (free, open source) software projects, most of the development is performed by a relatively small number of persons, the "core team". The stability and permanence of this group of most active developers is of great importance for the evolution and sustainability of the project. In this position paper we propose a quantitative methodology to study the evolution of core teams by analyzing information from source code management repositories. The most active developers in different periods are identified, and their activity is calculated over time, looking for core team evolution patterns.}, keywords = {core, cvs, cvsanaly, developers, evolution, gimp, scm}, isbn = {978-1-4244-3493-0}, doi = {10.1109/MSR.2009.5069497}, attachments = {https://flosshub.org/sites/flosshub.org/files/167core-evolution.pdf}, author = {Gregorio Robles and Jesus M. Gonzalez-Barahona and Herraiz, Israel} } @article {1084, title = {Dynamics of innovation in an "open source" collaboration environment: lurking, laboring, and launching FLOSS projects on SourceForge}, journal = {Industrial and Corporate Change}, volume = {17}, year = {2008}, note = {"For the purposes of this study, we are able to draw upon micro-level data pertaining to the activities undertaken during the period between the beginning of September 2000 and December 2002 by the entire cohort of 222,835 individuals who had registered on SF.net during the 14 months from September 1, 2000 through October 26, 2001." "The statistical analysis in this article is based upon an edited dataset (referred to here as the SFnetDataset) covering the SourceForge cohort of 222,835 individuals who registered on SF.net during the 14 months from September 1, 2000 through October 26, 2001." They appear to be using their own dataset which is from 2000-2001 even though this paper is from 2008}, month = {07/2008}, pages = {647 - 710}, abstract = {A systems analysis perspective is adopted to examine the critical properties of the Free/Libre/Open Source Software (FLOSS) mode of innovation, as reflected on the SourceForge platform (SF.net). This approach re-scales March{\textquoteright}s (1991) framework and applies it to characterize the {\textquotedblleft}innovation system{\textquotedblright} of a {\textquotedblleft}distributed organization{\textquotedblright} of interacting agents in a virtual collaboration environment, rather than to innovation within a firm. March (1991) views the process of innovation at the organizational level as the coupling of sub-processes of exploration and exploitation. Correspondingly, the innovation system of the virtual collaboration environment represented by SF.net is an emergent property of two {\textquotedblleft}coupled{\textquotedblright} processes: one involves the interactions among agents searching the locale for information and knowledge resources to use in designing novel software products (i.e., exploration), and the other involves the mobilization of individuals{\textquoteright} capabilities for application in the software development projects that become established on the platform (i.e., exploitation). The micro-dynamics of this system are studied empirically by constructing transition probability matrices representing the movements of 222,835 SF.net users among seven different activity states, which range from {\textquotedblleft}lurking{\textquotedblright} (not contributing or contributing to projects without becoming a member) to {\textquotedblleft}laboring{\textquotedblright} (joining one or more projects as members), and to {\textquotedblleft}launching{\textquotedblright} (founding one or more projects) within each successive 6-month interval. The estimated probabilities are found to form first-order Markov chains describing ergodic processes. This makes it possible the computation of the equilibrium distribution of agents among the states, thereby suppressing transient effects and revealing persisting patterns of project joining and project launching. The latter show the FLOSS innovation process on SF.net to be highly dissipative: a very large proportion of the registered {\textquotedblleft}developers{\textquotedblright} fail to become even minimally active on the platform. There is nevertheless an active core of mobile project joiners, and a (still smaller) core of project founders who persist in creating new projects. The structure of these groups{\textquoteright} interactions (as displayed within the 3-year period examined) is investigated in detail, and it is shown that it would be sufficient to sustain both the exploration and exploitation phases of the platform{\textquoteright}s global dynamics.}, keywords = {contributors, core, developers, roles, SFnetDataset, sourceforge, users, virtual communities, virtual organization, virtual organizations}, issn = {1464-3650}, doi = {10.1093/icc/dtn026}, author = {David, P. A. and Rullani, F.} } @conference {995, title = {Open Borders? Immigration in Open Source Projects}, booktitle = {Fourth International Workshop on Mining Software RepositoriesFourth International Workshop on Mining Software Repositories (MSR{\textquoteright}07:ICSE Workshops 2007)}, year = {2007}, pages = {6 - 6}, publisher = {IEEE}, organization = {IEEE}, address = {Minneapolis, MN, USA}, abstract = {Open source software is built by teams of volunteers. Each project has a core team of developers, who have the authority to commit changes to the repository; this team is the elite, committed foundation of the project, selected through a meritocratic process from a larger number of people who participate on the mailing list. Most projects carefully regulate admission of outsiders to full developer privileges; some projects even have formal descriptions of this process. Understanding the factors that influence the "who, how and when" of this process is critical, both for the sustainability of FLOSS projects, and for outside stakeholders who want to gain entry and succeed. In this paper we mount a quantitative case study of the process by which people join FLOSS projects, using data mined from the Apache web server, Postgres, and Python. We develop a theory of open source project joining, and evaluate this theory based on our data.}, keywords = {apache, core, joining, postgresql, python, team}, isbn = {0-7695-2950-X}, doi = {10.1109/MSR.2007.23}, attachments = {https://flosshub.org/sites/flosshub.org/files/28300006.pdf}, author = {Christian Bird and Gourley, Alex and Devanbu, Prem and Swaminathan, Anand and Hsu, Greta} } @conference {683, title = {Communication Networks in an Open Source Software Project}, booktitle = {OSS2006: Open Source Systems (IFIP 2.13)}, series = {IFIP International Federation for Information Processing }, volume = {203/2006}, year = {2006}, month = {2006///}, pages = {297 - 306}, publisher = {Springer}, organization = {Springer}, abstract = {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}, issn = {978-0-387-34225-2}, doi = {http://dx.doi.org/10.1007/0-387-34226-5_30}, attachments = {https://flosshub.org/sites/flosshub.org/files/Communication\%20Networks\%20in\%20an\%20Open\%20Source.pdf}, author = {Roberts, Jeffrey and Il-Horn Hann and Sandra Slaughter} } @conference {686, title = {Contributor Turnover in Libre Software Projects}, booktitle = {OSS2006: Open Source Systems (IFIP 2.13)}, series = {IFIP International Federation for Information Processing}, year = {2006}, pages = {273 - 286}, publisher = {Springer}, organization = {Springer}, abstract = {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 {\textquotedblleft}code gods{\textquotedblright}), while others are driven by several different developer groups over time (i.e. the project {\textquotedblleft}regenerates{\textquotedblright} 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}, doi = {http://dx.doi.org/10.1007/0-387-34226-5_28}, attachments = {https://flosshub.org/sites/flosshub.org/files/Contributor\%20Turnover\%20in\%20Libre\%20Software\%20Projects.pdf}, author = {Gregorio Robles and Gonzalez-Barahona, Jesus} } @article {90, title = {Core and periphery in Free/Libre and Open Source software team communications}, journal = {Proceedings of the 39th Annual Hawaii International Conference on System Sciences-Volume 06}, year = {2006}, abstract = {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{\textquoteright}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}, author = {Kevin Crowston and Kangning Wei and Li, Qing and Howison, James} } @conference {689, title = {Evolution of Open Source Communities}, booktitle = {OSS2006: Open Source Systems (IFIP 2.13)}, series = {IFIP International Federation for Information Processing}, year = {2006}, note = {"we took snapshots of its membership at regular intervals" "we chose a one year period" "we retrieve the list of core developers ordered by their number of inbound messages, as noted above."}, pages = {21 - 32}, publisher = {Springer}, organization = {Springer}, abstract = {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}, doi = {http://dx.doi.org/10.1007/0-387-34226-5_3}, attachments = {https://flosshub.org/sites/flosshub.org/files/Evolution\%20of\%20Open\%20Source\%20Communities.pdf}, author = {Weiss, Michael and Moroiu, Gabriella and Zhao, Ping} } @article {1079, title = {Are All Open Source Projects Created Equal? Understanding the Sustainability of Open Source Software Development Model}, journal = {AMCIS 2005 Proceedings}, number = {435}, year = {2005}, note = {uses first 300 most active projects on Sourceforge: {\textquoteright}Our data sample consists of 300 open source software development projects hosted in the Sourceforge.Net. They are the first 300 active projects ranked by Sourceforge.Net....Our dependent variable in the model to measure the success of the projects is the number of downloads. It is an essential variable to show how successful the project is. Generally, more number of downloads means a more successful project. Independent variables include: development status, project lifespan, number of developers, number of messages in the forums, number of mailing list, number of bug report, number of patch report, number of CVS report, number of file releases and also number of news release."}, abstract = {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{\textquoteright}s core developers{\textquoteright} role in the project{\textquoteright}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{\textquoteright} 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{\textquoteright} importance. Drawing the evidences from our extensive dataset of 300 open source projects, we demonstrated that core developers{\textquoteright} 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}, attachments = {https://flosshub.org/sites/flosshub.org/files/LongYuan.pdf}, author = {Long, J. and Yuan, M.J.} } @article {DBLP:journals/tse/Dinh-TrongB05, title = {The FreeBSD Project: A Replication Case Study of Open Source Development}, journal = {IEEE Trans. Software Eng.}, volume = {31}, number = {6}, year = {2005}, note = {" we obtained the necessary data from the [FreeBsd] CVS repository, the bug report database, and the e-mail archive. The CVS repository contains all of the code and related documentation that is committed to the project from 1993 until the present. The bug report database contains information describing all reported problems, as well as the status (such as fixed, under test, or open) of each problem. Each bug report is called a PR and assigned a reference number. The e-mail archive contains every e-mail message exchanged between the developers since 1994." d/l: research.cs.queensu.ca/~ahmed/home/teaching/.../F06/.../free-bsd.pdf}, pages = {481-494}, abstract = {Case studies can help to validate claims that open source software development produces higher quality software at lower cost than traditional commercial development. One problem inherent in case studies is external validity{\textemdash}we do not know whether or not results from one case study apply to another development project. We gain or lose confidence in case study results when similar case studies are conducted on other projects. This case study of the FreeBSD project, a long-lived open source project, provides further understanding of open source development. The paper details a method for mining repositories and querying project participants to retrieve key process information. The FreeBSD development process is fairly well-defined with proscribed methods for determining developer responsibilities, dealing with enhancements and defects, and managing releases. Compared to the Apache project, FreeBSD uses 1) a smaller set of core developers{\textemdash}developers who control the code base{\textemdash}that implement a smaller percentage of the system, 2) a larger set of top developers to implement 80 percent of the system, and 3) a more well-defined testing process. FreeBSD and Apache have a similar ratio of core developers to people involved in adapting and debugging the system and people who report problems. Both systems have similar defect densities and the developers are also users in both systems.}, keywords = {apache, bug reports, contributors, core, cvs, defect density, developers, email, email archive, freebsd, mailing list, scm, source code, users}, doi = {10.1109/TSE.2005.73}, attachments = {https://flosshub.org/sites/flosshub.org/files/DinhTrungBieman.pdf}, author = {Trung T. Dinh-Trong and James M. Bieman} } @article {121, title = {Two case studies of open source software development: Apache and Mozilla}, journal = {ACM Transactions on Software Engineering and Methodology}, volume = {11}, number = {3}, year = {2002}, note = {apache data sources: email, cvs, bug database regarding email: "We wrote Perl scripts to extract date, sender identity, message subject, and the message body that was further processed to obtain details on code changes and problem reports (see below). Manual inspection was used to resolve such things as multiple email addresses in cases where all automated techniques failed." (but the rest of the paper does not address this data source at all) mozilla data sources bugzilla, cvs }, pages = {309-346}, abstract = {According to its proponents, open source style software development has the capacity to compete successfully, and perhaps in many cases displace, traditional commercial development methods. In order to begin investigating such claims, we examine data from two major open source projects, the Apache web server and the Mozilla browser. By using email archives of source code change history and problem reports we quantify aspects of developer participation, core team size, code ownership, productivity, defect density, and problem resolution intervals for these OSS projects. We develop several hypotheses by comparing the Apache project with several commercial projects. We then test and refine several of these hypotheses, based on an analysis of Mozilla data. We conclude with thoughts about the prospects for high- performance commercial/ open source process hybrids.}, keywords = {apache, bug fixing, bug reports, bugzilla, change history, core, defect density, email, email archives, mailing list, mozilla, ownership, participation, productivity, scm, source code}, attachments = {https://flosshub.org/sites/flosshub.org/files/mockusFieldingHerbsleb2002.pdf}, author = {Audris Mockus and Roy Fielding and Herbsleb, J. D.} } @article {flosswp26, title = {A Case Study of Open Source Software Development: The Apache Server}, journal = {Proceedings of the International Conference on Software Engineering (ICSE 2000)}, year = {2000}, note = {We used the following archival sources of data: Developer email list (EMAIL). Concurrent Version Control archive (CVS). Problem reporting database (BUGDB).}, month = {June}, abstract = {According to its proponents, open source style software development has the capacity to compete successfully, and perhaps in many cases displace, traditional commercial development methods. We examine the development process of a major open source application, the Apache web server. By using email archives of source code change history and problem reports we quantify aspects of developer participation, core team size, code ownership, productivity, defect density, and problem resolution interval for this OSS project. This analysis reveals a unique process, which performs well on important measures.}, keywords = {apache, bug fix revisions, bugs, core, cvs, defect density, developers, email archives, participation, productivity, revision control, revision history, roles, scm, source code, team size}, attachments = {https://flosshub.org/sites/flosshub.org/files/mockusapache.pdf}, author = {Audris Mockus and Roy Fielding and Herbsleb, James} }