Doom RPG contains a number of references to the geek subculture.
Entrance contains a computer supposedly running an Operating System called UACNIX.
In Sector 2, the player encounters a locked door. A scientist gives the hint that the code is related to the structure of the level. An examination of the auto-map reveals that the level has been designed to read 1337, which is the code for the door. This is a leetspeak reference.
The game contains a number of computer consoles where map data can be downloaded. The player downloads this data using the Unix SCP program.