Forum OpenACS Q&A: Response to Getting ready for beta - tagging and branching CVS
Perforce is supposed to be good, though. The Linux folks have never used a source control system in the past because of Torvalds's personal bias against such things, but they've started using Bitkeeper recently and apparently like it.
So ... we can certainly explore if folks want to. CVS gets painful when you're trying to keep your private custom stuff merged with a public tree. Keeping the CVS tree for the project itself seems simple enough, it's just our users who will suffer if they are trying to keep a private tree synch'd with ours.
So it's probably our users who will be most motivated to explore a superior solution!