The Raycasting Game Maker is a free easy to use game editor that creates simple raycasting games in the style of Wolf3D. The finished game needs only two files to run, an executable and a pak file with the game data. The game runs in Windowed- or Fullscreen Mode and supports 16 and 32 bit color.
Figured I'd upload this picture of my current RGM project here. No name, no plot, just a theme - horrer/darkness. :-D