A version for OS X was developed by Aspyr and released in May 2014, and the Xbox 360 version was made backward compatible for the Xbox One in 2018. A separate version for the Nintendo DS, titled Modern Warfare: Mobilized, was also released on the same day. It was released worldwide on November 10, 2009, for Windows, PlayStation 3, and Xbox 360. It is the sixth installment in the Call of Duty series and the direct sequel to Call of Duty 4: Modern Warfare. Call of Duty: Modern Warfare 2 is a 2009 first-person shooter game developed by Infinity Ward and published by Activision.