Valve Corporation has released the playable demo for their upcoming survival horror game Left 4 Dead. The demo had previously been available via Steam to only those who had preordered the game. The Left 4 Dead demo gives you the opportunity to play two levels from one of the game's four storylines in either multiplayer and single player mode. The multiplayer portion of the demo however, will be shut down once the game hits general release on November 18th. The demo can be download for free from the links listed below.