Computer Game GURPS

[Dusqune]

Two major questions:

1: Has there ever been a computer/video game based off of GURPS? I think I heard something about Fallout being based off of GURPS at one point, but I've never played it, so I can't say if it retained that status.

2a: I don't know copyright law, so I'm going to throw this out there: If I decided to make a free, nonprofit text-based GURPS Game program, would that infringe any copyright laws?
2b: Lets say this pet project turned into something more; what would I have to do to actually sell it? What kind of permission would I have to get and how hard would that be?

Still in the inception phase of all this, and I may wake up tomorrow* and realize it was a dumb idea or something, but I figured I would post this and see where everything stands, at least.

*Or not, if the world is supposed to end? lol