open-source definition by Webster's New World
open-source definition by American Heritage Dictionary
open-source - Computer Definition
Also known as open source software (OSS). Software distributed under a license that makes the source code (i.e., program instructions) freely available to the end user. Such a license often encourages the user to modify the source code as long as the modifications are made freely available to other users, as well. Open source software generally is available at no charge, i.e., free. Linux is a classic example of successful open source software. See also software, Linux.
Open source proponents believe that software users should be able to view the source code and make changes to it to correct glitches or produce value-added features. The Linux operating system, for example, is 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 titles, and although 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, provide technical support and charge a fee, the most notable example being the Linux operating system (see Linux distribution). Fewer Bugs Vs. Too Many Cooks Open source proponents claim that the code in open source programs is continuously reviewed by new programmers, and bugs are weeded out more quickly. In addition, the wide variety of contributors leads to enhancements that might not otherwise be included. However, vendors of proprietary software counter by saying that having total control over the software is far superior; that the old saying "too many cooks spoil the broth" is especially true in software development. Advantages of Open Source The single major advantage is no licensing fees. A second advantage is flexibility. Users of open source software can modify the programs to fit their needs, and many companies use open source for this reason alone. Another advantage is the ability to fast track a project. Since there is no contract to sign, IT departments can use the software without waiting for contractual negotiations to be completed. Lastly, as long as there is 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 when it no longer generates enough profit. For more information, visit www.opensource.org and www.sourceforge.net. The Free and Open Source Communities 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 conforms to the free software movement, but there are occasional exceptions because the definition of free software is more strict (see free software). See Shared Source and open source hardware.