Unreal Tournament 2004, also known as UT2004 or UT2K4, is a futuristic first-person shooter computer game designed mainly for multiplayer gaming, although the game has a built in single-player mode that mimics multiplayer gaming by featuring AI-bots. Unreal Tournament 2004 is part of the Unreal series of games and is the sequel to 2002's Unreal Tournament 2003. Unreal Tournament 2004 was co-developed by Epic Games and Digital Extremes and published by Atari. The major addition to Unreal Tournament 2004 is the introduction of vehicles to the classic first-person shooter formula following in the footsteps of Tribes 2, Halo: Combat Evolved, and Battlefield 1942. Unreal Tournament 2004 also features great user interactivity with user-made mods, maps, and other add-ons.