It's a pen and paper rp system, though I suppose you could play it anywhere that provided a dice rolling option. It can be used for pretty much any genre, but it gets a bit unbalanced in high-tech campaigns.

The character building is point-based (you have a certain number of points that can be used to buy skills, advantages or stats; and you can get more points by taking disadvantages or quirks). It's fairly easy to pick up enough to play--it's kind of math-heavy for certain things, like building vehicles or robots (unless you use house-rules or something).

You can get a brief run-down of the rules for free here, if you're interested: www.sjgames.com/gurps/lite/