No, not really, but it's open to a bunch of stuff...
I'm not a big fan of GURPS, but Steve Jackson Games ROCKS!!! and I'm not just saying that because I live next door to the Corporte office either (Steve, where's my check?)
The thing I like about them is they turn out a consistantly good product, almost every sourcebook I have bought from them is Entertaining... witty and well researched as well a INFORMATIVE.. I mainly buy the stuff to use in other games