Tripwire Interactive is an American game development studio based in Roswell, Georgia, formed by members of the team that created the acclaimed Unreal Tournament 2004 mod, Red Orchestra: Combined Arms. Red Orchestra won top prize in the nVidia-sponsored Make Something Unreal competition. Their first retail product, Red Orchestra: Ostfront 41-45, was released over Valve's Steam service on March 14, 2006. They are also a license of Epic's Unreal Engine 3, which is used in their upcoming title Red Orchestra: Heroes of Stalingrad, scheduled for release in fall 2010.
Tripwire's second game, Killing Floor, was released on May 14, 2009. Like Red Orchestra, this game also began development as a UT2004 mod, later becoming a standalone retail title.