Stumbled upon this while browsing around.

http://www.vavoom-engine.com/about.php

seems to be a combo of doom/heretic/hexen/strife ported into one, not to bothered about the doom part since we already have one. From what i can gather you just need to supply the main iwad files from the original game you have bought,

Thought it would be a intresting one to consider

id imagine like the prboom whatever wad you have in the folder it boots unless specified otherwise in xterm.