Hi Jens,
We should maybe also consider graphical tools to access (and compare revisions, ...) repositories. CVS is supported very well, also subversion is supported by a few tools. I do most of the time work on the command line but a few users may depend on such software.
I prefer grafical CVS tools, but the best tool which I used is WinCVS for Windows ;-) Tools for Debian: Cervisia, gcvs, tkcvs don't support meny options. Maybe somebody prepare a solid tool for it?
Regards Wojciech Zareba