A little after its tenth anniversary, Amnesia: The Dark Descent is now open-source, allowing modders and aspiring game developers to delve into the title’s codebase to see how the horror masterpiece was created. You can download the source code for both The Dark Descent and its sequel, A Machine for Pigs (which itself started out as a mod), through GitHub.

As series developer Frictional Games points out, the annoucement doesn’t mean you can get the two titles for free. “It just means that people are free to use the source however they want as long as they adhere to the GPL3 license,” the studio said. “The game and all of its content is still owned by Frictional Games. Just like before.”