Steve Jackson Games
Steve Jackson Games was founded in 1980 by (no surprise here) Steve Jackson. We now publish books, games, and magazines for game fans.
Their best-known games include Munchkin, the irreverent game of dungeon crawling; Zombie Dice, the fast-paced game of brain-eating; GURPS, the "Generic Universal RolePlaying System"; OGRE, the classic simulation of future war; Car Wars, about battle on the highways; INWO, the trading card game of world domination; and the original Illuminati game on which INWO was based. Theye've released a lot of other games, too . . . too many to list right here.
They publish Pyramid magazine – the PDF magazine for roleplayers – which supports GURPS in all genres.