The open source Zircon engine ("DarkPlaces Mark V Project") is a modification DarkPlaces engine with a mouse driven menu everywhere, ALT-ENTER fullscreen/windowed switching and 88 other enhancements to support user/mapper/mod coder ease-of-use and optional conveniences for those interested in a "1996 Quake" experience. "csqc_full_width_height 1" in console when running Arcane Dimensions at this time It is hoped that some/many/all of these enhancements will eventually make it into official DarkPlaces. The Zircon engine seeks to keep full compatibility with DarkPlaces so either engine can be used interchangeably.
Dungeon Maker Lite Alpha with some imperfections listed in the readme, the largest one is that the engine appears to incorrectly handle "map_move" for origin brushes (func_rotating_door) .. if true, an engine update will also be required. Due to this one, there were smaller flaws (missing debris model, particle emitter wrong effect name, etc.) that will be corrected later. The rest of it works.