The first revision control system I ever used was called RCS. It was the pre-cursor to CVS and stored all revision data locally. It was nifty but very limited and not suited for group development. CVS was the first shared revisioning system I used. It was rock solid, IMHO. But it had a few big problems, like the inability to rename or move files. Everything had to be deleted and re-added.
Since those days, I've used several other revisioning systems: Perforce, Bitkeeper, Clearcase, Subversion and GIT.
