DOOM has a long and plentiful history of mods and maps, but this is unlike anything ever seen before.
As you can see, the mod brings Resident Evil 4's "The Mercenaries" mini-game to the hellish world of DOOM. Featuring three of the five orginal mercenaries, Leon, Hunk, and Krauser (sorry Ada and Wesker fans), the mod provides a definite change of pace. It even brings in each of the character's weapons, melee attack, quicktime dodges, and finishers.
Leon comes equipped with a punisher shotgun, chicago typewriter, hand cannon, and a selection of greneades.
Hunk retains his blacktail handgun, a riot shotgun, TMP submachine gun, and the Resident Evil version of the BFG, the PRL412.
Krauser goes Rambo with his bow and arrows, striker shotgun, TMP submachine gun, and his mutated arm-blade...thing.
The mod comes courtesy of "redield21" as he's known on YouTube, and he offers instructions on how to install the mod, as well as player controls.
The mod is available to download from either MediaFire or Rapidshare (but try MediaFire, at the time of this writing, the download doesn't seem to be available, as the "file owner's public traffic exhausted").
Just remember that this mod is only compatible with svn builds of zdoom.
With such impressive work, I'd love to see what this guy could do with DOOM 3 now that id has released the game's source code.