This started out as a mod for Unreal Tournament 2K3 and 2K4 that won Nvidia and Epic's Make Something Unreal contest. The grand prize was a free license for the Unreal Engine 2.5 and 3.0 game engines, and thus led to the formation of Tripwire Interactive and the retail release of Red Orchestra: Ostfront 41-45 in 2006. However, the original UT2K3 mod, called Red Orchestra: Combined Arms, was set on the eastern front during World War II. It took a new approach to tactical first-person shooter gaming by removing most of the graphical user interface and requiring players to rely on simulated 3D iron sights with added sway and character breathing, making it much more difficult to aim than it is in most standard first-person shooter games. The mod also added elements, such as the German MG42, the Soviet IS-2 heavy tank, grenade damage, and shell-shock.
"Take up arms as Germans or Soviets, fighting over the historical battlefields," the mod's creator said. "Enter the fray as anything from a simple rifleman to a tank commander. Play online alongside your comrades or play offline against intelligent AI infantry. In Red Orchestra, it's war."
Tripwire plans to release Red Orchestra: Heroes of Stalingrad in the second quarter of 2011 and will focus heavily on the Battle of Stalingrad.