Original: A further Doom game developed by id Software on their new id Tech 5 game engine, Doom 4, was announced in May 2008, although the game is not going to continue the story of Doom 3.
Simplified: It was created by iD Software, and came out in 2004. It was the first to not be based on the same game engine as Doom and Doom 2, and had 40 levels.