Fallout is a computer role-playing game developed by Black Isle Studios and published by Interplay in 1997. The game has a post-apocalyptic setting in the mid-22nd century, featuring an alternate history which deviates some time after WWII, where technology, politics and culture followed a different course. A huge success, it spawned many sequels, among them Fallout 2, Fallout: Tactics, Fallout: Brotherhood of Steel and recently Fallout 3 and Fallout: New Vegas. A MMO based on the Fallout universe is also currently in production. For more information check out the official website or the very comprehensive Fallout wiki.
Savage Worlds is a universal generic ruleset for role-playing games and miniatures wargames, written by Shane Hensley and published by Great White Games, first released in 2003. You can find a free PDF Test Drive edition on the Pinnacle Entertainment Group website.