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 .:: Document Index ::.
*The Open Source Definition
*The Halloween Documents
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*OSI Approved Licenses
*Peru prefers Open Source
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Policy Statements:
License Proliferation

 .:: OSD change log ::.
*1.0 identical to DFSG, except for addition of MPL and QPL to clause 10.
*1.1 added LGPL to clause 10.
*1.2 added public-domain to clause 10.
*1.3 retitled clause 10 and split off the license list, adding material on procedures.
*1.4 Now explicit about source code requirement for PD software.
*1.5 allow "reasonable reproduction cost" to meet GPL terms.
*1.6 Edited section 10; this material has moved.
*1.7 Section 10 replaced with new "Conformance" section.
*1.8 Section 1: replaced "may not" with "shall not".
*1.9 Section 9: removed rationale referring to the action of the GPL as Contaminat[ion].
* Section 10 added.
* Site History
 .:: Conformance to the OSD ::.

(This section is not part of the Open Source Definition.)

We think the Open Source Definition captures what the great majority of the software community originally meant, and still mean, by the term "Open Source". However, the term has become widely used and its meaning has lost some precision. The OSI Certified mark is OSI's way of certifying that the license under which the software is distributed conforms to the OSD; the generic term "Open Source" cannot provide that assurance, but we still encourage use of the term "Open Source" to mean conformance to the OSD. For information about the OSI Certified mark, and for a list of licenses that OSI has approved as conforming to the OSD, see the OSD Certification Mark page.


The Internet is full of open-source software in heavy commercial use. You might say, without open source, there would be no Internet.  Some of the most popular open source products in use today are:

Operating Systems

  • Linux: the most used Unix-like operating system on the planet. Versions have been run on anything from a handheld computers and regular PCs,  to the world's most powerful supercomputers. For a list of popular Linux distributions, look here.
  • FreeBSD, OpenBSD, and NetBSD: The BSDs are all based on the Berkeley Systems Distribution of Unix, developed at the University of California, Berkeley.  Another BSD based open source project is Darwin, which is the base of Apple's Mac OS X. 

Many of the router boxes and root DNS servers on the internet that keep the Internet working are based on one of the BSDs or on Linux.  A little birdie told us that Microsoft keeps BSD boxes hidden behind the scenes, in order to keep their Hotmail and MSN services working.  Not surprisingly, most of the software on top of the operating system that keeps the internet humming is also open source:


  • Apache, which runs over 50% of the world's web servers.
  • BIND, the software that provides the DNS (domain name service) for the entire Internet.
  • sendmail, the most important and widely used email transport software on the Internet.
  • Mozilla, the open source redesign of the venerable Netscape Browser, is retaking the ground lost by Netscape in the "browser wars".  It has quickly moved from 1.0 to 1.2, adding functionality, stability and cross-platform consistency that is not available from any other browser.  
  • OpenSSL is the standard for secure communication (strong encryption) over the internet.

The TCP/IP DNS, SSL, and e-mail servers are especially interesting because they're "category killers"; not only are they extremely capable and robust, they're so good that no commercial competition has ever been successful at replacing them as the most widely used product on their respective categories.

Programming Tools

  • Perl, Zope, and PHP, are popular engines behind the "live content" on the World Wide Web.
  • Powerful High Level  Languages like Python, Ruby, and Tcl/Tk owe much of their success and prevalence to the active community of developers that use them and continue their development.
  • The GNU compilers and tools (GCC, Make, Autoconf, and Automake, and others)  are arguably the most powerful, flexible, and extensible set of compilers in the world.  Almost all open source projects use them as their primary development tools.

Developer tools are especially well represented, because without open source programming tools, open source software would require proprietary tools to build and maintain it.   There are literally hundreds of thousands of popular open source packages, covering every imaginable category of software, and more are being developed every single day. Why? Because free Open Source software such a compelling idea, that once people begin to understand it, most people want to learn to use, promote, and make their own open source software to share with others.  You can also make money using open source software to deliver products and services to your customers: 

Open Source Companies

There is a lively business in selling open-source based solutions.  In particular, the services and support that customers need can be done most effectively with an entirely open-source system.   From top to bottom, open source companies can deliver a system that works, and that can continue to change and adapt to your business needs. 


In mid-June 1998, IBM chose the open-source Apache webserver to support and bundle with its WebSphere suite. It has since released the Secure Mailer in open source and launched the AlphaWorks site to disseminate cutting-edge IBM technology in source. Since that time, IBM's commitment to open source has grown substantially, from contributing a new journalled filesystem to Linux kernel development, to making  Linux the primary operating system on all their high end mainframe servers. 


Novell has become a player in this space with acquisitions of SUSE LINUX and Ximian in 2003, gaining both a powerful and well respected Linux Distribution, but also the creative minds at Ximian whose work on the Gnome Desktop and the Mono programming language are the envy of hacker types everywhere.


In March of 1999, Apple released the core layers of Mac OS X Server as an open source BSD operating system called Darwin. Apple was the first mainstream computer company to build its future around open source, and is partnering with the Apache Group, FreeBSD, NetBSD, and other open source developers to work on evolving the Mac OS X platform. Apple has expanded its involvement by open sourcing the QuickTime Streaming Server in April, and the OpenPlay network gaming toolkit in May.


HP has bet on Linux as the technology of choice for it's new line of high end servers based on the HP/Intel's jointly developed Itanium processor technology.  HP (Compaq IPAQ) handhelds can run Linux, too. HP also offers integrated support options for commercial customers who want support running open source systems on their HP or Compaq servers.  HP has yet to see the light in the consumer space, however.  


Sun uses Linux on a line of small servers originally made by Cobalt.  In addition, Sun supports open source development efforts such as the Forte IDE for Java, and the Mozilla web browser project.  


SGI has long funded prominent open source contributors, made many hardware donations (including big servers), and shown general friendliness toward open source. It sponsors the Samba project (an NT compatible file/print server running on all Unix systems that outperforms the Microsoft NT server), a port of Linux to SGI/MIPS machines, and is open-sourcing GLX (OpenGL extensions to X11) In August 1999 SGI open-sourced the XFS journaling file system. SGI promises this trend will continue and strengthen in the future with even more significant contributions, and has launched an open-source site.  Since that time, SGI has dropped most support for it's proprietary Unix variant, and focused its energy on running Linux on its high end products.


Sharp's new Zaurus handhelds (SL-5500, SL-5600) run exclusively on Linux.  These handhelds are not only the ultimate in cool open-source toys, they are also personal organizers, and powerful mobile computing  tools.  Expect more great open source offerings from from Sharp if this PDA continues to do well in the market.


Cyclades manufactures routers, rack-mounted remote access servers, multiport-serial and networking cards. They have a long history of cooperating with the open-source world. Their drivers for Linux and FreeBSD are open-source, and their rack-mounted hardware runs open source Linux.

Red Hat Software

An extremely successful Linux vendor. They have shipped more paid copies of Red Hat Linux than any other vendor.  In their last quarter (2002) they surprised the post-dot-com economy, that assumed Linux was old news, by returning a profit.   All indications are that they will continue to succeed, both in delivering open source technology, and in developing a compelling profitable business model. 


ActiveState is a privately-held corporation with investors that include O'Reilly & Associates, Inc. ActiveState leads the industry in providing professional tools for Perl, Python, and Tcl/tk developers. In addition to maintaining the ActivePerl distribution on Windows and Unix, ActiveState provides sophisticated integrated tools, with professional support, for commercial software developers.

Sleepycat Software, Inc.

Sleepycat Software builds, distributes, and supports Berkeley DB (BSDDB), the open-source embedded database system. Berkeley DB offers programmers reliable, scalable database services with very little overhead. It has a small footprint and requires virtually no database administration by end users. Sleepycat's customers include many of the leading open-source projects, as well as Fortune 500 companies whose own products are proprietary. The complete source code for Berkeley DB is available for download from Sleepycat's Web site.

Covalent Technologies

Covalent Technologies develops commercial software enhancements for the Apache Web server platform and provides full commercial support packages for Apache. Covalent maintains its role as a founding member of the Apache Project and actively participates in the research, development and administrative efforts of the Apache Software Foundation.

Zope Corporation

Zope Corporation developed the Zope content management system, which provides web sites with dynamic content creation and management tools, useable by both programmers and non-programmers.  Their core technology (the Zope engine) is entirely open source, and is powered by the open source Python programming language.  

Open Source in Government and Non-Profit

If the many recent news announcements are any indication, governments are beginning to wake up to the potential  for open source software used in government offices, and are starting to understand the benefits of  open source to the whole community.   Expect to see more and more public-sector and non-profit organizations around the world utilizing open source software to build a better tomorrow for all of us!

prepared for OSI by Warren Postma

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