High Quality Content by WIKIPEDIA articles! Left 4 Dead 2 (abbreviated as L4D2) is a cooperative first-person shooter video game. It is the sequel to Valve Corporation`s award-winning Left 4 Dead. The game launched on November 17, 2009, for Microsoft Windows and Xbox 360 in the United States and November 20 in Europe; in 2010, Left 4 Dead 2 was made available to the Steam client for Mac OS X. It builds upon the cooperatively-focused gameplay of the original and uses Valve`s proprietary Source engine, the same game engine used in Left 4 Dead. The game made its world premiere at E3 2009 with a trailer during the Microsoft press event.