lzdoom (lightweight Doom/Doom2/etc engine)

LZDoom is a legacy GZDoom fork with lower system requirements than
GZDoom. In particular, it supports 32-bit x86, which GZDoom no longer
goes.

gzdoom is only a game engine. To actually play the game, you'll need the
game data (IWAD file) from one or more of the supported games. These
include Doom, Ultimate Doom, Final Doom, FreeDoom, Heretic, Hexen,
and Strife.  Place the .wad file(s) in /usr/share/games/doom.

If you don't own any of the supported games, you can install one or more
of these slackbuilds.org packages to get a playable game:

- freedoom
- doom_shareware_data
- heretic_shareware_data
- hexen_demo_data
- chexquest3