The Annihilation Engine for Source is an addon for Valve's Source engine providing many new functions and features for aspiring mod and game developers to use to build their own unique worlds using gameplay features and effects currently not available as standard within the Source engine. The Annihilation Engine is under constant development and is currently being used by Annihilation Game Studios to create four distinct mods for Valve's Source engine to be released throughout 2009 and 2010. A public API for the engine will be released on the 1st of May 2009 allowing other modders to use the engine as a base for their own mods.