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

Basic Concepts

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

The 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)

Software Categories (Sourceforge)

Development Status

Software Categories (FreeBSD Ports)

Operating Environments

Operating System

Language

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
• Xfig
• 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
• CVS
• Subversion

Text Processing

• TeX / LaTeX / MiKTeX
• Docbook
• groff
• aspell
• OpenOffice / KOffice/Abiword
• Expat XML Parser

Web and Application Servers

• Apache Web Server
• Jakarta Tomcat
• JetSpeed
• JBoss

Desktop Applications

• Mozilla
• Putty
• Xine
• Open Office
• Gnumeric
• Evolution (calendar, meeting, ...)
• FireFox
• Thunderbird
• Gaim IM

Open Source Repositories

• Sourceforge (http://www.sourceforge.net): open source repository
• Freshmeat (http://www.freshmeat.net): Unix software directory
• CPAN (http://www.cpan.org): Perl module directory
• Jakarta (http://jakarta.apache.org): open source solutions on the Java platform (e.g. Tomcat)
• Savannah (http://savannah.gnu.org): GNU software repository
• CTAN (http://www.ctan.org): TeX software repository

Influence on Product Development

Advantages

• Many existing elements available for reuse (what)
• Flexible reuse granulariy (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: CVS.
• Adoption of software engineering processes
  • version control
  • peer reviews,
  • version control
  • peer reviews
  • issue tracking
  • release engineering
  • regression testing.
• Learn from the source

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

• Freshmeat (http://freshmeat.net/),Sourceforge (http://sourceforge.net/). These two 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

• 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.

• 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.

• 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? ( http://www.spinellis.gr/pubs/jrnl/2004-IEEESW-OSS/html/ge-intro.html). IEEE Software, 21(1):28–33, January/February 2004.

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 Last change: Saturday, March 11, 2006 9:50 am
 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.