"Day of Defeat has quietly been one of the most played online action games for the past three years," said Gabe Newell, president and founder of Valve. "Day of Defeat: Source represents a major leap forward in both graphics and gameplay, and pushes the Source engine harder than any other Source project. " DoD: Source takes the classic teamplay of DoD and expands the experience with Source, the engine technology Valve created for Half-Life 2 and it's next generation of games. With this technology, DoD: Source offers state of the art graphics with optimized versions of popular maps and all new player, weapon and world models, plus support for HDR lighting. DoD: Source leverages the power of the Source engine by introducing advanced sound technology to provide a more immersive soundscape and integrated physics simulation technology for ragdolls and physically simulated objects throughout each map.