I’ve just uploaded the skeleton of a fairly extensive system of tables for procedurally creating fantasy worlds. It’s pretty fun to tinker around with, if you’ve got a few hours and a big sheet of paper for a map…
You could use it with any RPG system, but it’s designed to slot seamlessly into GURPS. (For example, the various “Climates” and “Terrain Types” match up as far as possible with the established specialties of the Survival skill. Stuff like that.)
Plus, like all my tables, these use only six-sided dice – and wherever possible, they use the good ol’ 3d6!
This world creation system can be used on its own, but it also slots into the rest of the (admittedly somewhat crazy) Collaborative GURPS Play system I’ll be uploading piece by piece over the coming weeks/months.