Frictional Games Has Released Source Code For Two Amnesia Games As FOSS Under The GNU GPLv3
Swedish Frictional Games AB has released the source code for their Amnesia: The Dark Descent (2010) and Amnesia: A Machine For Pigs (2013) games as free open source software under the GNU GPLv3 license. The game assets have not been made available under any free license so the full games remain proprietary software.
The games are written in C++. They use SDL for input processing, OpenGL to render the graphics and the OpenAL API for audio.
The Swedes have not released any game assets under a free license, so the full games remain non-free proprietary software.
"I also hope this release can be of help to anyone wanting to create their own engine or just wanting to learn more about game programming. While the code is not the greatest in places and the tech used is not the latest, it is a fully contained game engine in a fairly easy-to-understand package. It is also a testament that it is possible to do this sort of thing, even with a very limited team."
A game bundle with Amnesia: The Dark Descent and Amnesia: A Machine For Pigs is currently on a 25% sale for €60 or about $70 in the Steam store. The Amnesia games are available for Linux, Windows and macOS.