The Odyssey Engine is a computer game engine developed by BioWare and has exclusively been used to create three dimensional computer role-playing games. The engine is BioWare's third license-able engine, after the Infinity Engine and the Aurora Engine. The engine was first used by BioWare to produce the critically acclaimed Star Wars: Knights of the Old Republic released on November 19, 2003. The engine was later licensed to Obsidian Entertainment to develop the sequel, Star Wars: Knights of the Old Republic II: The Sith Lords first released December 6, 2004. The engine was based on the Aurora Engine (the one used in Neverwinter Nights) and added 3D backgrounds and character facial motions.