CVS/repository for Altium
I use SVN, but not within Altium, I just check in the SchDoc, PcbDoc, OutJob, and PrjPCB. The nice thing is that the Altium version control tools (like diff) work just fine, and I didn't ever have to configure Altium for version control - it just saw that the files were under SVN and knew how to handle them. It works quite well, especially with the Altium files. I also tag releases when I send them off to manufacturing.