For the sake of completion VCS does have GUI, new one is called DVE and
is quite powerful. I wouldn't comment (yet) on its stability, it has
lot of good features (that you usually find/expect in such GUI).
Specifically I like their assertion debug stuff.

Last time I played with Simvision (NC's GUI), it looked very stable and
very nice to use. I particularly liked their TCL interface - very
powerful indeed.

HTH
Ajeetha
www.noveldv.com