This article was published on GameDev.net back in 2002. In 2008 it was revised by the original author and included in the book Business and Production: A GameDev.net Collection, which is one of 4 books collecting both popular GameDev.net articles and new original content in print format.Sharing source goes back as early as the 1950's when the SHARE group was formed to exchange code for IBM mainframes. IBM released the source to the software for their mainframes, allowing changes for specific needs. This updated code was passed around the SHARE group, creating the earliest form of open source. In 1985, The Free Sofware Foundation was formed by Richard Stallman, to to promote the freedom to distribute and modify computer software without restriction. Stallman had been working in the AI department at MIT and left in 1984 to began writing GNU free software. (GNU is pronounced "guh-NEW" and it stands for "GNU's Not Unix"). The Free Software Foundation (fsf.org) defines free software is a matter of liberty, not price. To understand the concept, you should think of "free" as in "free speech," not as in "free beer." Free software is a matter of the users' freedom to run, copy, distribute, study, change and improve the software. In 1997, a paper written by Eric S. Raymond, The Cathedral and the Bazaar triggered a series of events that led to the forming of the Open Source Institute. One of the more significant events at the time was Netscape releasing the source to their browser. That project is still alive and well with various projects like the Firefox browser and the NVU (nvu.com) HTML editor. The OSI was jointly founded by Eric Raymond and Bruce Perens in late February 1998 , as a general educational and advocacy organization. Next, it is necessary to understand what open source software is and what it is not. Open source in its purist sense is software that has the source code available to anyone who desires it. That individual is free to use the code as he sees fit, however any modifications to the code must be made available for everyone to use and modify, under the same conditions. According to opensource.org, "Open source promotes software reliability and quality by supporting independent peer review and rapid evolution of source code." It's not source code that you download from a website with permission to redistribute and modify and also to add additional restrictions to it. It's not a free program like Artweaver (artweaver.de) that's made available to the public for free without the source code. It's not source code released into public domain where the rights to the code are forfeited. It is also not source code that's distributed freely with a clause saying it has to be non-profit. Open source creates a system of free access of information for the greater good of the project.