OHJ-1860 Software Systems Seminar: Global Software Development. Open-source software development By Antti Rasmus

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OHJ-1860 Software Systems Seminar:

Global Software Development Global Software Development Open-source software development

11.12.2007

By Antti Rasmus

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Outline

• Open-source software (OSS) development

• Motivation: IDC study on open source in global software

• Case GNOME

• Architecture

• Organization

• Communication

• Case Apache

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Open-Source Software

• Open-source software (OSS) is built by potentially large number of voluntary people

• “a great babbling bazaar of differing agendas and approaches”

–E. Raymond [1]

• There are supporting companies and paid developers as well

• Extreme case of globally distributed development

• Developer roles are not clearly defined or tasks aren't assigned

• Developers in arbitrary locations - rarely or never meet face to face

• Communication by means of mailing lists, forums, IRC, IM

• Lacks coordination: no plans, system-level design, schedules or defined processes? [2]

• However, software development management systems

• GNU Savannah, SourceForge, BountySource

• continues..

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Open-Source Software

• Extreme case of globally distributed development

• Unknown people

• Multiple cultures and languages

• “Because open source works in a distributed environment, it presents an opportunity for developing countries to participate in frontier innovation” [3]

in frontier innovation” [3]

• Political differences

• Competition between developers

• Volunteers and company paid developers

• Despite of the bazaar nature, still high quality software!

• Apache, Linux kernel, GCC, Mozilla, Perl, GNOME,...

• Open-source ideology works great in distributed environment

• However, challenge for companies to fully exploit

• Different drivers, processes, licenses => Isolate OSS! [4]

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IDC study on open-source in GSD

• IDC is global market intelligence firm

• Open Source in Global Software: Market Impact, Disruption, and Business Models, July 2006 [5]

• Surveyed 5,000 developers in 116 countries

• Conclusions

• OSS is “the most significant all-encompassing and long-term trend that the software industry has seen since the early

1980s."

• OSS "play a role in the life-cycle of every major software

category, and will fundamentally change the value proposition of packaged software for customers."

• OSS is being used by 71 percents of developers worldwide

• OSS is "in production" at 54 percent of the surveyed

developers' organizations

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Case GNOME

• Based on GNOME, a case of open source global software development by Daniel German, 2003 [6]

• GNOME project was founded in 1996

• In 2003, 500 developers around the world, 2+ MLOCs

• Infrastructure

• GNU toolkit (gcc, make, emacs, etc.)

• CVS

• Bugzilla

• GNU Mailman

• Unix as development platform

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Case GNOME - Requirement sources

• Vision:

• “GNOME should be completely free software”

• "free as in free speech" not "free as in free beer” -Free Software Foundation

• Reference applications:

• “GNOME should have most if not the same functionality as these reference applications”

• MS Excel, gv, Outlook, Lotus Notes

• Asserted requirements

• Requirements gathered from general discussion on mailing lists, not necessarily from particular requirement analysis

• A prototype

• New feature ideas are frequently proposed in a form of a

implemented prototypes. The rest decides whether to adapt it

or not

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Case GNOME - Architecture

• Big project is divided into manageable modules

• Four main groups of modules

• Libraries (19 modules)

• Core applications (4)

• Applications (16)

• Other (several dozens)

• At least one maintainer per module

• Oversees the development

• Coordinates and integrates the contributions of other developers

• If a module grows too big, it is broken into submodules

• Evolution (mail client) is broken into more than 20 modules

• UI, mail libraries, filter, importers, documentation, translation,...

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Case GNOME - Module maintainer

• Module maintainers serve the roles of leaders

• provide vision

• divide their module into tasks

• attract developers to the project

• keep the project together and prevent forking

• The success of OSS project depends on the ability of its maintainers to divide it into parts which are small enough and independent, so that

• developers do not have to communicate

• developers' work has minimal impact to work of others

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Case GNOME - The paid employees

• Several companies involved

• RedHat, Sun Microsystems, Ximian

• Paid employees are usually responsible for project design and coordination, testing, documentation and bug-fixing

bug-fixing

• Usually less attractive to volunteers

• Companies make sure that development continues at a steady pace

• “In the case of Evolution, the top 10 contributors (which account for almost 70% of the CVS commits) are all Ximian employees.”

• Volunteers still play very important role

• maintainers, contributors, bug hunters, documenters, beta testers, etc.

• internationalization is only done by volunteers in GNOME

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Case GNOME - Foundation

• In 2000, the GNOME Foundation was instituted

• Four entities

• members (any contributor)

• board of directors (11 democratically selected people)

• advisory board (non-profit organizations and companies)

• executive director

• Committees

• consist of volunteer developers

• for organizing conference, web site updating, system administration of GNOME machines, maintaining the membership list of the Foundation, etc.

• Release teams

• schedules module releases

• keeps track overall development of the project

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Case GNOME - Communication

• Developers are distributed around the world

• Mailing lists for different purposes

• end users, particular modules, announcements

• is where the decision making happens

• IRC

• informal discussion without agenda

• Web sites

• lots of information for contributors

• GUADEC, the GNOME conference

• discussion, interaction and training

• GNOME summaries

• Posted to a mailing list in every two weeks

• news, most active modules and developers, numbers of bugs

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Case Apache (in 2002)

• Apache is the most widely deployed web server [2]

• Almost 400 people contributed code

• CVS commits managed by Apache Group

• Apache Group started with 8 members in 1995

• In 2002, 25 members in AG

• used exclusively mailing lists to communicate, and a minimal voting system

• A bug reporting system and a newsgroup that anyone could use were lower priority communication channels

• One AG member volunteers to be a release manager

• identifies critical problems preventing the release

• coordinates fixes and declares a version stable

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References

• [1]The Cathedral and the Bazaar

• E.S. Raymond, http://www.catb.org/~esr/writings/cathedral-bazaar/cathedral- bazaar/

• [2] Two Case Studies of Open Source Software Development: Apache and Mozilla

• A. Mockus et al., ACM Transactions on Software Engineering and Methodology, Vol. 11, No. 3, July 2002, pp 309–346.

• [3] Open-Source Software Development and Distributed Innovation

• B. Kogut, A. Metiu, Oxf Rev Econ Policy Vol. 17, No. 2, June 2001, pp. 248-264

• [4] Global software development

• R Granat, Software Platforms, Nokia, August 2007

• Online http://www.jyu.fi/it/laitokset/cs/en/infwest/global_swd

• [5] Open Source in Global Software: Market Impact, Disruption, and Business Models

• Anthony C. Picardi, et al., July 2006

• Summarized on Linuxdevices.com

• (http://www.linuxdevices.com/news/NS8982719739.html)

• [6] The GNOME project: a case study of open source, global software development, Daniel M. German