The digital retail disc version was released in North America and Australia on November 18, 2008, and in Europe on November 21, 2008. Development on the game was completed on November 13, 2008, and two versions were released digitally: A downloadable digital version, released on November 17, 2008, and a digital retail disc version, with a release date determined by region. The game uses Valve's proprietary Source engine, and is available for Microsoft Windows, Xbox 360 and Mac OS X. Left 4 Dead is a 2008 multiplayer survival horror game developed by Valve South and published by Valve.
