Treyarch NGL is a proprietary 3D Game Engine developed by Treyarch. The engine has been retired by Treyarch who are currently using a continually modified version of the third iteration of the IW Engine.The game is generally associated with first-person shooters due to its use in the Call of Duty video game series, however, it has been used by Treyarch and other companies in games of various genres, the major of these games coming out in 2002.