Well this is quite fun to see. Amnesia: The Dark Descent has gained a Redux mod that rebuilds the graphics engine behind the game to provide Vulkan on Linux and DirectX 12 on Windows. It's not just adding it for the heck of it though, the developer said it will also correct some graphics issues in the original game while adding in new graphics options like HBAO+.
This is possible because Frictional Games opened up the source code for multiple of their games (GitHub). This particular Redux mod reworks the graphics using The Forge, a cross-platform rendering framework.
Don't expect perfection from the Redux mod just yet, as the developer said you can play it through but you may encounter some issues while they continue to improve it.
This is why open source is great. Anyone can come along and improve older games, give them a graphical boost and ensure they keep working long into the future.