CrossVC is a graphical version-control program. It is available for Windows (only CrossVC XXL), Mac OS X and Unix (Linux, Solaris, BSD).
You can manage the versions of source-code files. The access to all versions of a file is possible everytime. You can track the modifications from version to version.
Together with CVS or Subversion CrossVC provides network-wide access to a repository for all members of a team. The team members can work on the files concurrently, they can merge their modifications, can develop on multiple branches and much more.