With Amnesia: Rebirth releasing in less than a month, Frictional Games has announced that their 2010 title Amnesia: The Dark Descent is now open source.
“This doesn’t mean that the game is suddenly free. It just means that people are free to use the source however they want as long as they adhere to the GPL3 licence. The game and all of its content is still owned by Frictional Games. Just like before.” – Frictional Games
Amnesia: The Dark Descent is a survival horror game where your only tools to survive are running and hiding. There is no gunslinging or the like.
The purpose of making this title open source is to give those interested in game development something they can use to that end. The game will still be sold as before, but arguably the only thing standing between you and playing it for free is the fact that you have to build it from the source code. There are no executable files, only the source and instructions on how to build it.
If you’d like to get into game development, this might be a nice place to start.