Apache Subversion (often abbreviated SVN, after the command name svn) is a software versioning and a revision control system distributed under a free license. Developers use Subversion to maintain current and historical versions of files such as source code, web pages, and documentation. Its goal is to be a mostly-compatible successor to the widely used Concurrent Versions System (CVS).
‒ Courtesy of Wikipedia
There are currently 5 groups being archived from Subversion (subversion.apache.org).