Frictional Games has released the source code for Amnesia: The Dark Descent and Amnesia: A Machine for Pigs under the GPL v3 license. This move is seen as a way to give back to the community, which has created over a thousand mods and addons for the game. The source code includes the game code, editor code, and various features such as shadow mapping and physics-based interaction. The release is intended to facilitate modding, learning, and potentially the creation of new games or game engines.