OBLIGE is a random level generator for various classic games, including
DOOM, DOOM II, Heretic, and Quake. The goal is to produce high quality
levels which are fun to play.

A Doom (or Heretic, or Quake) engine is required if you actually want to
play the levels you generate. Currently there are builds on SBo for zdoom,
gzdoom, prboom, chocolate-doom, odamex, skulltag, and maybe a few more.

Also required: the data file(s) for whichever game(s) you're playing
(registered versions, not shareware):

Game:            File:
Doom             doom.wad
Doom II          doom2.wad
Heretic          heretic.wad
Quake            pak0.pak and pak1.pak