Call of Duty is a first person and third-person shooter video game series franchise. The series began on the PC, and later expanded to consoles and handhelds, and several spin-off games have also been released alongside the main series. The majority of the games in the series have been set primarily in World War II, with the exception of Call of Duty 4: Modern Warfare and Call of Duty: Modern Warfare 2, which are set in modern times. The Call of Duty video games are published and owned by Activision and published for Macs by Aspyr Media and have been developed primarily by Infinity Ward and Treyarch, with other games being developed by Gray Matter Interactive, Spark Unlimited, Pi Studios, Amaze Entertainment, Rebellion Developments, and n-Space, using a variety of game engines including the id Tech 3, the Treyarch NGL, and the IW 4.0. Other products in the franchise include a line of action figures designed by Plan-B Toys, a card game created by Upper Deck, and a comic book mini-series published by WildStorm.
As of November 27, 2009, total sales for the Call Of Duty series have surpassed 55 million units worldwide, taking $3 billion in retail sales in the process.