We are very pleased to introduce Open Source Development, Communities and Quality. The International Conference on Open Source Systems has come to its fourth edition – OSS 2008. Now, Free, Libre, and Open Source software is by all means now one of the most relevant subjects of study in several disciplines, ranging from information technology to social sciences and including also law, business, and political sciences. There are several conference tracks devoted to open source software with several publications appearing in high quality journals and magazines. OSS 2008 has been organized with the purpose of being the reference venue for those working in this area, being the most prominent conference in this area. For this th reason OSS 2008 has been located within the frameworks of the 20 World Computer Congress, WCC 2008, in Milan, the largest event of IFIP in 2008. We believe that this conference series, and the IFIP working group it represents, can play an important role in meeting these challenges, and hope that this book will become a valuable contribution to the open source body of research.

Welcome to the 5th International Conference on Open Source Systems! It is quite an achievement to reach the five-year mark – that’s the sign of a successful enterprise. This annual conference is now being recognized as the primary event for the open source research community, attracting not only high-quality papers, but also building a community around a technical program, a collection of workshops, and (starting this year) a Doctoral Consortium. Reaching this milestone reflects the efforts of many people, including the conference founders, as well as the organizers and participants in the previous conferences. My task has been easy, and has been greatly aided by the hard work of Kevin Crowston and Cornelia Boldyreff, the Program Committee, as well as the Organizing Team led by Björn Lundell. All of us are also grateful to our attendees, especially in the difficult economic climate of 2009. We hope the participants found the conference valuable both for its technical content and for its personal networking opportunities. To me, it is interesting to look back over the past five years, not just at this conference, but at the development and acceptance of open source software. Since 2004, the business and commercial side of open source has grown enormously. At that time, there were only a handful of open source businesses, led by RedHat and its Linux distribution. Companies such as MySQL and JBoss were still quite small.

Computer software and technologies are advancing at an amazing rate. The accessibility of these software sources allows for a wider power among common users as well as rapid advancement in program development and operating information. Free and Open Source Software in Modern Data Science and Business Intelligence: Emerging Research and Opportunities is a critical scholarly resource that examines the differences between the two types of software, integral in the FOSS movement, and their effect on the distribution and use of software. Featuring coverage on a wide range of topics, such as FOSS Ecology, graph mining, and project tasks, this book is geared towards academicians, researchers, and students interested in current research on the growing importance of FOSS and its expanding reach in IT infrastructure.

This thesis approaches the phenomenon of open source software (OSS) from a managerial and organisational point of view. In a slightly narrower sense, this thesis studies commercialisation aspects around community-driven open source. The term ‘community-driven’ signifies open source projects that are managed, steered, and controlled by communities of volunteers, as opposed to those that are managed, steered, and controlled by single corporate sponsors. By adopting a business ecology perspective, this thesis places emphasis on the larger context within which the commercialisation of OSS is embedded (e.g., global and collaborative production regimes, ideological foundations, market characteristics, and diffuse boundary conditions). Because many business benefits arise as a consequence of the activities taking place in the communities and ecosystems around open source projects, a business ecology perspective may be a useful analytical guide for understanding the opportunities, challenges, and risks that firms face in commercializing OSS. There are two overarching themes guiding this thesis. The first theme concerns the challenges that firms face in commercialising community-driven open source. There is a tendency in the literature on business ecosystems and open source to emphasise the benefits, opportunities, and positive aspects of behaviour, at the expense of the challenges that firms face. However, business ecosystems are not only spaces of opportunity, they may also pose a variety of challenges that firms need to overcome in order to be successful. To help rectify this imbalance in the literature, the first theme particularly focuses on the challenges that firms face in commercialising community-driven open source. The underlying ambition is to facilitate a more balanced and holistic understanding of the collaborative and competitive dynamics in ecosystems around open source projects. The other theme concerns the complex intertwining of community engagement and profit-oriented venturing. As is acknowledged in the literature, the subject of firm-community interaction has become increasingly important because the survival, success, and sustainability of peer production communities has become of strategic relevance to many organisations. However, while many strategic benefits may arise as a consequence of firm-community interaction, there is a lack of research studying how the value-creating logics of firm–community interaction are embedded within the bigger picture in which they occur. Bearing this bigger picture in mind, this thesis explores the intertwining of volunteer community engagement and profit-oriented venturing by focusing on four aspects that are theorised in the literature: reinforcement, complementarity, synergy, and reciprocity. This thesis is designed as a qualitative exploratory single-case study. The empirical case is Joomla, a popular open source content management system. In a nutshell, the Joomla case in this thesis comprises the interactions in the Joomla community and the commercial activities around the Joomla platform (e.g., web development, consulting, marketing, customisation, extensions). In order to achieve greater analytical depth, the business ecology perspective is complemented with ideas and propositions from other theoretical areas, such as stakeholder theory, community governance, organizational identity, motivation theory, pricing, and bundling. The findings show that the common challenges in commercialising community-driven open source revolve around nine distinct factors that roughly cluster into three domains: the ecosystem, the community, and the firm. In short, the domain of the ecosystem comprises the global operating environment, the pace of change, and the cannibalisation of ideas. The domain of the community comprises the platform policy, platform image, and the voluntary nature of the open source project. And finally, the domain of the firm comprises the blurring boundaries between private and professional lives, the difficulty of estimating costs, and firm dependencies. Based on these insights, a framework for analysing community-based value creation in business ecosystems is proposed. This framework integrates collective innovation, community engagement, and value capture into a unified model of value creation in contexts of firm–community interaction. Furthermore, the findings reveal demonstrable effects of reinforcement, complementarity, synergy, and reciprocity in the intertwining of volunteer community engagement and profit-oriented venturing. By showing that this intertwining can be strong in empirical cases where commercial activities are often implicitly assumed to be absent, this thesis provides a more nuanced understanding of firm involvement in the realm of open source. Based on the empirical and analytical insights, a number of further theoretical implications are discussed, such as the role of intersubjective trust in relation to the uncertainties that commercial actors face, an alternative way of classifying community types, the metaphor of superorganisms in the context of open source, issues pertaining to the well-being of community participants, and issues in relation to the transitioning of open source developers from a community-based to an entrepreneurial self-identity when commercialising an open source solution. Furthermore, this thesis builds on six sub-studies that make individual contributions of their own. In a broad sense, this thesis contributes to the literature streams on the commercialisation of OSS, the business value and strategic aspects of open source, the interrelationships between community forms of organising and entrepreneurial activities, and the nascent research on ecology perspectives on peer-production communities. A variety of opportunities for future research are highlighted. Denna avhandling undersöker fenomenet öppen källkod, ’open source’, ur ett lednings och styrningsperspektiv. Mer konkret studeras aspekter på kommersialisering av ett community-drivet open source projekt (OSS, open source software). Uttrycket ’community-drivet’ hänvisar till open source projekt som drivs och styrs av volontärgrupper, till skillnad från open source projekt som drivs och styrs av enskilda företag. Genom att tillämpa ett affärsekologiperspektiv fokuserar denna avhandling på det vidare sammanhang som karaktäriserar kommersialisering av OSS, såsom globala och kollaborativa produktionssystem, värderingarna öppenhet och samarbete, marknadsstrukturer, och diffusa organisationsgränser. Aktiviteterna i open source communityn och dess kringliggande ekosystem kan bidra till många fördelar för företag, och därför kan ett affärsekologiperspektiv vara en användbar analytisk lins för att förstå de möjligheter, utmaningar och risker som företag står inför när de kommersialiserar OSS. Två övergripande teman lyfts fram i denna avhandling. Det första temat handlar om de utmaningar som företag står inför när de kommersialiserar community-driven OSS. Det finns i litteraturen om affärsekologier och open source en tendens att betona fördelar, möjligheter och positiva aspekter på beteende på bekostnad av att undersöka utmaningar som företag står inför. Affärsekologier innebär dock inte enbart möjligheter för företag, utan kan också orsaka en rad utmaningar som företag behöver hantera för att lyckas. Med utgångspunkt i denna obalans i litteraturen fokuserar det första temat på de utmaningar med kommersialisering av community-driven OSS. Detta görs för att bidra till en mer balanserad och holistisk förståelse av den på samma gång kollaborativa och konkurrerande dynamiken i affärsekologin runt ett open source projekt. Det andra temat handlar om sammanflätningen (intertwining) mellan community-deltagande och vinstdrivande verksamhet. Såsom det framgår i litteraturen har frågan om samverkan mellan företag och communities blivit allt viktigare, eftersom communityernas överlevnad, framgång och hållbarhet har blivit strategiskt viktiga för många organisationer. Även om många strategiska fördelar kan uppstå som en följd av samverkan mellan företag och communities saknas forskning om hur värdeskapande uppstår i en vidare kontext. Med ett bredare perspektiv i åtanke undersöker denna avhandling sammanflätningen av frivilligt community-deltagande och en vinstdrivande verksamhet genom att fokusera på fyra aspekter av sammanflätning som förekommer i litteraturen: förstärkning, komplementaritet, synergi, och ömsesidighet. Denna avhandling är utformad som en kvalitativ utforskande fallstudie. Det empiriska fallet är Joomla, ett innehållshanteringssystem som bygger på open source. Inom ramen för avhandlingen undersöks fallet i termer av samspel inom Joomla-communityn och de kommersiella aktiviteterna som sker runt Joomla-plattformen (t.ex., webbutveckling, rådgivning, marknadsföring, anpassningar, och extensions). För att uppnå ett analytiskt djup kompletteras affärsekologiperspektivet med idéer och förslag från andra teoretiska områden, såsom intressentmodellen, community-styrning, företagsidentitet, motivationsteori, prissättning, och buntning. Resultaten visar att utmaningarna med kommersialisering av community-driven OSS kretsar kring nio olika faktorer som kan grupperas i tre områden: ekosystemet, communityn, och företaget. Ekosystemsfaktorerna innefattar den globala verksamma miljön, förändringshastigheten och kannibalisering av idéer. Community-faktorerna innefattar plattformspolicy, plattformsimage, och att deltagandet i open source projektet sker på frivillig basis. Slutligen innefattar företagsfaktorerna suddiga gränser mellan privatliv och arbetsliv, svårigheten att uppskatta kostnader samt beroendeförhållanden mellan företag. Baserat på dessa insikter föreslås en modell för att analysera communitybaserad värdeskapande i affärsekologier. Modellen integrerar kollektiv innovation, community-deltagande, och value capture i en holistisk modell för community-baserad värdeskapande i kontexten samverkan mellan företag och communities. Vidare beskrivs effekterna av sammanflätningen av frivilligt community-deltagande och vinstdrivande verksamhet i termer av förstärkning, komplementaritet, synergi, och ömsesidighet. Genom att visa att sammanflätningen av frivilligt community-deltagande och vinstdrivande verksamhet kan vara stark i fall där det ofta antas implicit att kommersiella aktiviteter inte förekommer ger denna avhandling en mer nyanserad förståelse av företags roll i kontexten open source. Baserat på empiriska och analytiska insikter diskuterar denna avhandling ett antal teoretiska konsekvenser, såsom rollen som intersubjektiv tillit spelar i förhållande till den ovisshet som kommersiella aktörer står inför, ett alternativt sätt att klassificera community-typer, metaforen superorganismer i kontexten open source, community-deltagares välbefinnande, samt hur open source utvecklare hanterar övergången från en community-baserad självidentitet till en entreprenöriell självidentitet vid kommersialisering av OSS. Dessutom ger de sex delstudier som avhandlingen bygger på egna bidrag som presenteras i respektive delstudie. I stora drag bidrar denna avhandling till litteraturen om kommersialisering av OSS, affärsmässiga och strategiska aspekter på open source, samspelet mellan community-driven entreprenörsverksamhet samt den framväxande forskning som använder ett affärsekologiperspektiv för att studera kollegial produktion baserad på allmännytta. En mängd olika möjligheter för framtida forskning lyfts fram.

This book constitutes the refereed proceedings of the 7th International IFIP WG 2.13 Conference on Open Source Systems, OSS 2010, held in Salvador, Brazil, in October 2011. The 20 revised full papers presented together with 4 industrial full papers and 8 lightning talks were carefully reviewed and selected from 56 submissions. The papers are organized in the following topical sections: OSS quality and reliability, OSS products, review of technologies of and for OSS, knowledge and research building in OSS, OSS reuse, integration, and compliance, OSS value and economics, OSS adoption in industry, and mining OSS repositories.

Page 26: How can I avoid off-by-one errors? Page 143: Are Trojan Horse attacks for real? Page 158: Where should I look when my application can't handle its workload? Page 256: How can I detect memory leaks? Page 309: How do I target my application to international markets? Page 394: How should I name my code's identifiers? Page 441: How can I find and improve the code coverage of my tests? Diomidis Spinellis' first book, Code Reading, showed programmers how to understand and modify key functional properties of software. Code Quality focuses on non-functional properties, demonstrating how to meet such critical requirements as reliability, security, portability, and maintainability, as well as efficiency in time and space. Spinellis draws on hundreds of examples from open source projects--such as the Apache web and application servers, the BSD Unix systems, and the HSQLDB Java database--to illustrate concepts and techniques that every professional software developer will be able to appreciate and apply immediately. Complete files for the open source code illustrated in this book are available online at: http://www.spinellis.gr/codequality/

In recent years, the way open source software is developed has taken hold as a valid alternative to commercial proprietary methods, as have the products themselves, e.g., the Linux operating system, Apache web-server software, and Mozilla Firefox browser. But what is open source software? How is the open source community organized? What makes this new model successful? What effects has it had and might it have on the future of the IT industry, companies and government policies? These and many other questions are answered in this book.The first chapter gives a brief history of the open source community and the second chapter takes a close look at the relationship between intellectual property rights and software, both open source and proprietary. The next three chapters consider the who, the open source community, the how, software development both within and outside the community, and the what, open source projects and product quality. Chapters 6 and 7 focus on the different users of open source software: companies and governments respectively. These are followed by two chapters that interpret the phenomenon, first from an organizational point of view in Chapter 8 and then using the theory of complex adaptive systems in Chapter 9. The last chapter explores the current and potential applications of the concept underlying open source software in other fields.