subversion

Apache Subversion, also known as svn, is a centralised version control system. Version control systems allow many individuals (who may be distributed geographically) to collaborate on a set of files (source code, websites, etc). Subversion began with a CVS paradigm and supports all the major features of CVS, but has evolved to support many features that CVS users often wish they had.

Only use this tool against systems you own or are explicitly authorized to test — see the disclaimer.