In addition to the other methods, the OpenSees source code is now stored using Apache Subversion (SVN) software. SVN provides the means to store not only the current version of a piece of source code, but a record of all changes (and who made those changes) that have occurred to that source code. Use of SVN is particularly common on projects with multiple developers, since SVN ensures changes made by one developer are not accidentally removed when another developer posts their changes to the source tree.
Anyone can check out the code via anonymous SVN access, but only certain people have the ability to check in. Those people, basically, are people who I trust not mess up the code. Read our document on hacking OpenSees to find out how to get the ability to check in and how programmers without this ability can check in their code.
Anonymous SVN Access
svn co svn://opensees.berkeley.edu/usr/local/svn/OpenSees/trunk OpenSeesUsers of Windows machines are encouraged to look at TortoiseSVN

