Call of Duty: Modern Warfare 2 (or Call of Duty 6: Modern Warfare 2) is a first-person shooter video game developed by Infinity Ward and published by Activision for the Xbox 360 and PlayStation 3 video game consoles and the Microsoft Windows operating system. Officially announced on February 11, 2009, the game was released worldwide on November 10, 2009. It is the sixth installment of the Call of Duty series and the direct sequel to Call of Duty 4: Modern Warfare, continuing the same storyline, with Call of Duty: Modern Warfare 3 set to end the storyline. It was released in conjunction with two other Call of Duty games: Call of Duty: Modern Warfare: Mobilized for the Nintendo DS, and Call of Duty: Modern Warfare: Reflex, a port of Call of Duty 4 adapted by Treyarch for the Wii console. In addition, a comic book series based on one of the game's characters was also produced, entitled Modern Warfare 2: Ghost.
Modern Warfare 2 has received very positive reviews from various gaming websites, attaining a 94% aggregate score on Metacritic, with praise stemming primarily from its in-depth multiplayer component. Upon its release, the game sold approximately 4.7 million copies worldwide in 24 hours. On June 15, 2010, Activision confirmed that the game had sold over 20 million copies worldwide and it is the best-selling game of all time in the UK, and the second best-selling game of all time in the U.S.