Many artists are using the Quake and Wolfenstein graphics engine to create "art".

Feng Mengbo
After months of playing the visceral action game Quake III Arena (Q3A) with others online, Feng Mengbo used the games ability to create custom game characters, to develop his own version for his performance piece (called Q4U).

Nullpointer - Q
"This project is the results of my initial attempts to exploit the source code of the original Quake1 game. In this case I chose to transform the graphics engine to produce a highly abstract environment that not only reduced the actual 3D ambitions of the original to minimal 2D planes but also exposed the pixel mechanics behind the software. "

q3apd
q3apd uses activity in QuakeIII as control data for the realtime audio synthesis environment Pure Data.

WOLFENSHMOOG
4 computers were network conected and the shooting game "return to castle wolfenstein" was running on it. all the sound output of these computers were conected to 3 other computers. on these, 3 musicians were real time processing the sounds generated by the game.