A cross-platform video game (or multi-platform)is one that is released on two or more systems at the same time. There are times when a video game may be exclusive for some period of time (usually several months) and then release for a competing system. This is known as a timed exclusive. Several games were released on the Xbox and Xbox 360 that were later released on the PC, notably the Halo series and Gears of War. These are still considered cross-platform, although they are console exclusives for the Xbox 360.