open source

Refers to software that is distributed with its source code so that end user organizations and vendors can modify it for their own purposes. Most open source licenses allow the software to be redistributed without restriction under the same terms of the license. For the complete, official definition of open source, visit www.opensource.org/docs/osd. For a list of approved open source licenses, visit www.opensource.org/licenses.

There are thousands of open source programs, and although they are used on most platforms, they are particularly common in the Unix world. Major examples are the Linux operating system, Apache Web server and JBoss application server. See Linux, Apache and JBoss.

Free and Paid
A great amount of open source software is available at no charge, and many open source projects are developed by a community of volunteers. However, there are commercial vendors that enhance open source software and charge a fee, the most notable example being a distribution of Linux (see Linux distribution).

Free and Open Source
In the late 1990s, open source software was derived from "free software," meaning free of restrictions and why the phrase "free and open source software" is often used. Whereas the "free software" movement promotes the user's freedom as an ethical issue, the philosophy of open source focuses on the practical benefits when users cooperate with each other. Nearly all open source software is free software, but there are occasional exceptions because the definition of free software is more strict (see free software).

Peer Review
Open source proponents claim that because the source code is continuously reviewed by new programmers, it eventually produces a more bug-free product. In addition, the wide variety of contributors provides enhancements and refinements that would take much longer with proprietary software or never be added.

Vendors of proprietary software counter by saying that "too many cooks spoil the broth!" They maintain that having complete control over software ultimately results in better products. Clearly there is good and bad software from both camps, but there is empirical evidence that open source has advantages. "Software Industry vs. Software Society: Who Wins in 2020?" is a provocative article about the subject by Michael Tiemann, president of the Open Source Initiative (www.computerlanguage.com/2020.pdf).

Useful Software May Last Longer
A distinct advantage of open source is that as long as there is even one remaining, devoted contributor, the software will continue to be enhanced. In the world of proprietary, commercial software, a useful program that users may truly love is often abandoned if it does not generate sufficient profit compared to other products. For more information, visit www.opensource.org and www.sourceforge.net. See free software, Shared Source and open source hardware.

open source

a. intellectual property, esp computer source code, that is made freely available to the general public by its creators

b. (as modifier): open source software

(philosophy, legal)

open source - A method and philosophy for software licensing and distribution designed to encourage use and improvement of software written by volunteers by ensuring that anyone can copy the source code and modify it freely.

The term "open source" is now more widely used than the earlier term "free software" (promoted by the Free Software Foundation) but has broadly the same meaning - free of distribution restrictions, not necessarily free of charge.

There are various open source licenses available. Programmers can choose an appropriate license to use when distributing their programs.

The Open Source Initiative promotes the Open Source Definition.

The Cathedral and the Bazaar. was a seminal paper describing the open source phenomenon.

Open Sources - O'Reilly book with full text online.

Articles from ZDNet.