A nonprofit corporation dedicated to managing and promoting the Open Source Definition (see: open source). The distribution terms in OSI's Open Source Definition model require the following: The software must be redistributed to anyone without restriction; the source code must be made available so the receiving party may improve or modify it; and the license provides the option of allowing improved versions to use a different name or version number than that of the original software. Open Source is the result of a long-time movement toward software that is developed and improved by a group of volunteers cooperating together on a network. (Right on, we say.) Many parts of the Unixoperating system were developed this way, including today's most popular version, Linux.