A generator app for generating random mazes, that are then compiled into Doom 2 compatible PWAD's (Patch WAD files). You can create single levels, or whole campaigns (32 levels). This is for use in either the proprietary software, or many of the open source ports available.
With a combination of this and at least two other software packages (a free Doom 2 source port, and a free Doom IWAD) you can create a completely free dungeon crawls game.
Note, if you're downloading the compiled exe...