The Open Source Landscape

History

• Initially software was tied to the hardware and free
• Organized collections: SHARE, ACM collected algorithms on tape
• 1970s Academic distribution of Unix in source code form
• 1983: Richard Stallman and the GNU Project
• Late 1980s: X Window System
• 1991: Linus Torvalds and the Linux kernel
• 1998: Netscape releases Mozilla; the Open-Source Movement

Free and "Free" Software

• Public Domain Software
• Open-Source Software
• Shared-Source Software
• Free Software
• Shareware
• Adware
• Spyware

The Open Source Definition

• Free redistribution
• Easy availability of source code
• Allow derived works
• Integrity of the author's source code
• No discrimination against persons or groups
• No discrimination against fields of endeavor
• Automatic distribution of license with the software
• License must not be specific to a product
• License must not restrict other software

Software Categories (FreeBSD Ports)

System Software

Operating Systems

• The Linux kernel
• Linux distributions
• FreeBSD
• NetBSD
• OpenBSD
• DragonFly
• Mach
• Plan 9
• Hurd
• Microsoft Windows (if you are a government)

Databases

• mySQL
• PostgreSQL
• SQLite
• HSQLDB

Emulators

• Bochs X86 emulator
• Wine (Wine Is Not an Emulator)
• Samba
• Cygwin

Language Processors

• The GNU compiler collection
• Perl
• Python
• Ruby
• PHP
• Tcl/Tk
• Mono (.NET re-implementation)
• Shells

Graphics

Applications and Libraries

• Ghostscript
• PNG
• GD
• FreeType
• Gnuplot
• GraphViz
• GMT
• Gimp
• Inkscape
• VLC or Mplayer

Environments

• X Window System
• KDE
• Gnome

Development Tools

• GNU binary and text tools
• GNU Emacs
• vim
• jEdit
• Eclipse
• KDevelop
• Dev-C++
• JUnit
• Boost C++ Libraries
• dOxygen
• autoconf
• bison and flex
• make / ant
• Bugzilla
• git / Subversion / CVS

Text Processing

• TeX / LaTeX / MiKTeX
• Docbook
• groff
• aspell
• Libre Office / Apache OpenOffice / Calligra Suite
• Expat XML Parser

Web and Application Servers

• Apache Web Server
• Jakarta Tomcat
• JetSpeed
• JBoss

Desktop Applications

• Putty
• Xine
• Open Office
• Gnumeric
• Evolution (calendar, meeting, ...)
• Firefox (web browser)
• Thunderbird (email client)
• Pidgin (instant messaging)

Open Source Software Forges

• GitHub (http://github.com): social coding
• Google Code (http://code.google.com/): Home of Android, Google Web Toolkit, App Engine, and other projects
• Sourceforge (http://www.sourceforge.net): open source repository
• java.net (http://www.java.net): development projects related to Java technology
• Freecode (http://freecode.com/): Unix software directory
• CPAN (http://www.cpan.org): Perl module directory
• Apache Software Foundation projects; around 100 high-quality and visibility projects
• Savannah (http://savannah.gnu.org): GNU software repository
• CRAN (http://cran.r-project.org/mirrors.html): R Project archiv
• CTAN (http://www.ctan.org): TeX software repository

Influence on Product Development

Advantages

• Many existing elements available for reuse (what)
• Flexible reuse granularity (how)
• Easier porting (where)
• Improve, fix, support

Problems

• Divergent evolution
• Code bloat
• Inadvertently deep dependencies
• Dependency management
• Licensing
• Quality control

Development Process Advantages

• Adoption of sophisticated development platforms and tools
  • operating systems: GNU/Linux and FreeBSD,
  • databases: PostgreSQL and MySQL,
  • application servers: JBoss,
  • optimizing compilers: gcc,
  • integrated development environments: Eclipse KDevelop,
  • build managers: make and ant,
  • version control management systems: git, Subversion.
• Adoption of software engineering processes
  • version control
  • peer reviews
  • issue tracking
  • release engineering
  • regression testing.
• Learn from the source
• Easier procurement
• Adherence to open standards

Development Process Problems

• Contribute to maintenance
• Forks: effort duplication and waste
• Integration of multiple developlemnt processes
• Less attention to
  • strategic planning
  • detailed requirement elicitation
  • testing
  • organized support.

License Distribution (Sourceforge)

Legal Exposure

• Proprietary code coexistsence with GPL
• Distribution of copyrights
• Assuming liability for all the code use
• Dynamic loading of code has is own licensing issues
• The BSD-like licenses allow for proprietary forks
• Packaging companies often offer value

Web sites

• GitHub (http://github.com/), Freecode (http://freecode.com/), Sourceforge (http://sourceforge.net/). These three Web sites are hubs hosting thousands of open source projects. Developers can use them to search for software to reuse, browse the corresponding forums and mailing lists, and download packages.
• The Open Source Initiative (http://www.opensource.org/). The open source home page. It includes a list with all software licenses that classify a software distribution as open source and also a list of successful open source projects.
• LAMP (http://www.onlamp.com/). The LAMP Model is a widely used recipe for implementing dynamic Web sites. It entails using the GNU/Linux operating system; the Apache Web Server; the MySQL Database Engine; and Perl, Python, or PHP as a scripting language. The model demonstrates how you can use open source to implement Web-based enterprise systems.
• MIT (http://opensource.mit.edu/). The open source directory maintained by the MIT Sloan School of Management includes a large catalog of scientific publications related to open source.
• Free & Open Source Software @ Greece (http://www.open-source.gr/).
• Finally, a of sources of interesting reading are listed at the daemon web site (http://daemon.di.uoa.gr/daemon/readings).

Further Reading

• Stephanos Androutsellis-Theotokis, Diomidis Spinellis, Maria Kechagia, and Georgios Gousios. Open source software: A survey from 10,000 feet. Foundations and Trends in Technology, Information and Operations Management, 4(3–4):187–347, 2010. (doi:10.1561/0200000026 (http://dx.doi.org/10.1561/0200000026))

• Michael A. Cusumano. The Business of Software: What Every Manager, Programmer, and Entrepreneur Must Know to Thrive and Survive in Good Times and Bad. The Free Press, New York, 2004.

• J. Feller and B. Fitzgerald. Understanding Open Source Software Development. Addison-Wesley, Reading, MA, 2001.

• E. Von Hippel. Innovation by user communities: Learning from open source software. Sloan Management Review, 42(4):82–86, Summer 2001.

• Maria Kechagia, Diomidis Spinellis, and Stephanos Androutsellis-Theotokis. Open source licensing across package dependencies. In Costas Vassilakis and Nikolaos Tselikas, editors, PCI 2010: Proceedings of 14th Panhelenic Conference on Informatics, pages 27–32, Los Alamitos, CA, USA, September 2010. IEEE Computer Society. (doi:10.1109/PCI.2010.28 (http://dx.doi.org/10.1109/PCI.2010.28))

• Brian W. Kernighan and P. J. Plauger. Software Tools. Addison-Wesley, Reading, MA, 1976.

• John Lions. Lions' Commentary on Unix 6th Edition with Source Code. Annabooks, Poway, CA, 1996.

• T. R. Madanmohan and Rahul De'. Open source reuse in commercial firms. IEEE Software, 21(6):62–69, November/December 2004. (doi:10.1109/MS.2004.45 (http://dx.doi.org/10.1109/MS.2004.45))

• David G. Messerschmitt and Clemens Szyperski. Software Ecosystem—Understanding An Indispensable Technology and Industry. MIT Press, Cambridge, 2003.

• Eric S. Raymond. The Cathedral and the Bazaar: Musings on Linux and Open Source by an Accidental Revolutionary. O' Reilly and Associates, Sebastopol, CA, 2001.

• Eric S. Raymond. The Art Of Unix Programming. Addison-Wesley, 2003.

• J. Sandred. Managing Open Source Projects. John Wiley and Sons, New York, 2001.

• Diomidis Spinellis and Clements Szyperski. How is open source affecting software development?. IEEE Software, 21(1):28–33, January/February 2004.

• Diomidis Spinellis. Open source and professional advancement. IEEE Software, 23(5):70–71, September/October 2006. (doi:10.1109/MS.2006.136 (http://dx.doi.org/10.1109/MS.2006.136))

• Diomidis Spinellis. Cracking software reuse. IEEE Software, 24(1):12–13, January/February 2007. (doi:10.1109/MS.2007.9 (http://dx.doi.org/10.1109/MS.2007.9))

• Diomidis Spinellis. Choosing and using open source components. IEEE Software, 28(3):96, 95, May/June 2011. (doi:10.1109/MS.2011.54 (http://dx.doi.org/10.1109/MS.2011.54))

Exercises and Discussion Topics

1. Examine which software categories are over or underepresented in open source software repositories. Discuss why this might be the case.
2. What criteria will you use for determining the project to contribute?
3. Describe the business model behind a packaging company. Is a similar business model used in another, non-software, area? Why (not)?
4. Consider adopting some of the programs we described to improve your productivity.
5. Learn a scripting language, like Ruby, Python, or Perl.
6. Compile a Swiss-army-knife CD with all the open source software you would want to have with you on a desert island.

The Full Open Source Definition

Introduction

Open source doesn't just mean access to the source code. The distribution terms of open-source software must comply with the following criteria:

1. Free Redistribution

The license shall not restrict any party from selling or giving away the software as a component of an aggregate software distribution containing programs from several different sources. The license shall not require a royalty or other fee for such sale.

2. Source Code

The program must include source code, and must allow distribution in source code as well as compiled form. Where some form of a product is not distributed with source code, there must be a well-publicized means of obtaining the source code for no more than a reasonable reproduction cost preferably, downloading via the Internet without charge. The source code must be the preferred form in which a programmer would modify the program. Deliberately obfuscated source code is not allowed. Intermediate forms such as the output of a preprocessor or translator are not allowed.

3. Derived Works

The license must allow modifications and derived works, and must allow them to be distributed under the same terms as the license of the original software.

4. Integrity of The Author's Source Code

The license may restrict source-code from being distributed in modified form only if the license allows the distribution of "patch files" with the source code for the purpose of modifying the program at build time. The license must explicitly permit distribution of software built from modified source code. The license may require derived works to carry a different name or version number from the original software.

5. No Discrimination Against Persons or Groups

The license must not discriminate against any person or group of persons.

6. No Discrimination Against Fields of Endeavor

The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research.

7. Distribution of License

The rights attached to the program must apply to all to whom the program is redistributed without the need for execution of an additional license by those parties.

8. License Must Not Be Specific to a Product

The rights attached to the program must not depend on the program's being part of a particular software distribution. If the program is extracted from that distribution and used or distributed within the terms of the program's license, all parties to whom the program is redistributed should have the same rights as those that are granted in conjunction with the original software distribution.

9. License Must Not Restrict Other Software

The license must not place restrictions on other software that is distributed along with the licensed software. For example, the license must not insist that all other programs distributed on the same medium must be open-source software.

*10. License Must Be Technology-Neutral

No provision of the license may be predicated on any individual technology or style of interface.

Origins: Bruce Perens wrote the first draft of this document as "The Debian Free Software Guidelines", and refined it using the comments of the Debian developers in a month-long e-mail conference in June, 1997. He removed the Debian-specific references from the document to create the "Open Source Definition."

Copyright © 2004 by the Open Source Initiative (http://www.opensource.org)

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 Last change: Wednesday, March 6, 2013 4:13 pm
 Unless otherwise expressly stated, all original material on this page created by Diomidis Spinellis is licensed under a Creative Commons Attribution-Share Alike 3.0 Greece License.