Call of Duty 4: Modern Warfare is a first-person shooter video game developed by Infinity Ward and published by Activision for the PlayStation 3, Windows, and the Xbox 360. It is scheduled for release for Mac OS X in the third quarter of 2008. It is the fourth installment of the Call of Duty video game series, excluding expansion packs. The game breaks away from the World War II setting of previous games in the series and is instead set in modern times. The game is the first in the series to be rated Mature in North America. The title and game details were announced on April 25, 2007, and the game was released worldwide between November 6, 2007 and November 9, 2007. It became available on Steam on November 6, 2007 for pre-purchase, and was available to play on November 12, 2007. The game was in development for two years. It uses a proprietary game engine, and includes features that include true world-dynamic lightning, HDR lighting effects, dynamics shadows, and depth of field.
The story is centered around a fictional near-future conflict involving the United States, the United Kingdom, and Russia, who are fighting against Russian ultranationalists in civil war torn Russia, and rebels that have staged a coup d'état in a small Middle Eastern country. It is told from the perspectives of a United States Marine and British SAS operative, and is set in multiple locations, including the Middle East, Azerbaijan, Russia, and Prypiat, Ukraine. The multiplayer portion of the game features various game modes, and contains a leveling system that allows the player to unlock additional weapons, weapon attachments, and camouflage schemes as they