PrBoom+

PrBoom+ is a version of the classic 3D shoot'em'up game Doom, originally
written by id Software.

To launch the game (specify the path to the .wad file as an argument):
prboom-plus -iwad doom/doom.wad

To have music in the game, you have several options:
1. 'opl2' audio backend: MIDI music played by opl2
2. 'sdl' audio backend: You need a Timidity directory with MIDI instruments
(better quality than opl2. Set the path to timidity.cfg in the prboom-plus.cfg
file (default: PROGDIR:Timidity/timidity.cfg)
3. 'sdl' audio backend: You can upload .ogg files to the "music" folder. File
names must be in Doom format (you can view the required names in the .cfg file)
3. 'sdl' audio backend: If you have an additional .wad file with music, you can
use it 

Starting the server for multiplayer:
prboom-plus-game-server -N 2 -w doom/doom.wad -p 5030

Joining a network game:
prboom-plus -iwad doom/doom.wad -net 192.168.100.27 (replace with your server's
IP)

Note: All players in a network game should have framecap set in their options!