Introduction to Open Source

Imed Hammouda, adjunct professorTampere University of Technology

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Open Source vs. Free Software

Free software (1983) is: A philosophy A social movement FSF

Open source (1998) is: A business model A development methodology OSI

Both approaches share a common vision on access to source code:

Freedom to run Freedom to study Freedom to redistribute Freedom to improve

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Open Source – The Method

“Open source is a development method for software that harnesses the power of distributed peer review and transparency of process.”

“The promise of open source is better quality, higher reliability, more flexibility, lower cost, and an end to predatory vendor lock-in.”

Ideally, participation in the community need not be restricted in any ways.

Practice can however make the difference!

In addition, adequate tools are needed!

[www.bugzilla.org]

Open Source – The Community

Non-profit organization SponsorsCommercial enterprisesThe Onion model of communitiesCommunities around OSS projects

Volunteer-based• Ideology, freedom, sharing

Company-based• Business, funded developers

MixedDifferent types of communities

Linux: Project centric MySQL: Business centric Eclipse: Foundation centric

Projec t leaderC ore member

Active developerPeripheral developer

Bug fixerBug reporter

R eaderPass ive user

Open Source – The License

She who writes the code owns the copyright, and can decide the license

A way to publish software with the right... ... to make copies and distribute software ... to have access to the software's source code ... to improve software

License With Copyleft (GPL, LGPL, Mozilla (weak copyleft) etc.) Without Copyleft (BSD, Apache) Viral effect – open and proprietary can touch only if allowed Dual License – if you own the copyright, then you decide which

license

OS licenses are nowadays accepted by US authorities Court of Appeals for the Federal Circuit (THE "IP" court in the US) has

upheld a free copyright license. [http://lessig.org/blog/2008/08/ huge_and_important_news_free_l.html]

Open Source – The Business

Internal usage + competition strategy Software As A Service (SAAS) Consulting (technical, legal, strategic,…) Integration, aggregation, and customization Retailing and distribution Product and software know-how Process and methodology know-how Services and product support Training and recruiting Certification and quality assurance Substitution/migration Dual licensing Documentation (books, user manuals, etc) Other process-related issues (testing, deployment, etc) Hardware + other related software (extra features, protocols, configurations) + media

content Commercial software on top of OSS Platform specialization/adaptation, localization IT infrastructure …

Open Source – The Technology Life Cycle

Efficient and Effective Development (http://www.itea-cosi.org/)

Open Source – The Cost

Open Source – The Design

Core system

Extension

Extension

Extension

Plugin

Plugin

Plugin

• Designs often remain undocumented

• Architecture recovery tools helpful

• In general attention geared towards running code

• Aim at designing (large) separate entities of open source and proprietary code

Thank You!

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