Raft

Raft is a video game engine that runs within Game Maker Studio that I wrote intermittently for about 10 years. (2014 - ?)
It powers SUPER 3-D CRUNK BROS. here is a boring video about it:

It can load MAP files from Quake, supports Half-Life WAD textures for map files, and has a logic system very similar to the one in LittleBigPlanet 2.

the idea was that many people could collaborate long-distance on a Game Maker game without needing to synchronize the game project file between one another. people could make maps and content on their own instances of the game completely isolated from other developers, and then merge it all together.

In 2024, there are much better options for game development. this ran on GM:S 1.4. And to be frank, I'm not very good at programming, I just have weird, ambitious ideas. So most of everything I just mentioned was impressive in concept yet duct-taped together and was honestly a nightmare to work with.