To date there have been 4 versions of Guitar Hero released.
The Original Guitar Hero was released in 2005 for play only on the Sony Playstation 2 (PS2).
Guitar Hero II was released in 2006. Initially for the PS2, a later version was released in 2007 for the Microsoft Xbox 360 (Xbox 360).
Guitar Hero Encore: Rocks the 80s was released in 2007, again only for play on the PS2.
In late 2007 Guitar Hero III: Legends of Rock was released. This version allowed play on the PS2, Playstation 3, Xbox 360, and the Nintendo Wii.