Announcing Oblige, the DooM engine random level generator. Get it here: http://repo.openpandora.org/?page=detail&app=Oblige
Go fetch one of the doom engine pnds: zdoom, cocoa-doom, Doomrunner. If you don't have the original data from doom, get FreeDooM (which comes with the Cocoa-doom pnd). Then just add the .wad same as you would any other addon wad.