Our company was using Rational Clearcase for version control about 6 years ago. The developers decided it was way to clunky, error prone and WAY too expensive. We introduced CVS and it has been working fine for a few years now. CVS is widely known, stable and simple. I looked into using SVN a few years ago but the clients were unusable at that time. This year, the SVN discussion came to life again and some of my collegues started playing with it after I mentioned it as being a step forward from CVS.