In a similar spirit to Freedoom, for Quake fans perhaps you'll want to take a look at LibreQuake, which aims to do a similar thing to allow you to play Quake content with completely open source software.
copyright used to only by 14 years plus a one time extention of another 14 years. Since quake 1 was released in 1996, it would be free for all to play with. Imagine being free to play with our own culture without all these work around.
Imagine being free. I can't honestly. Like a fish ,whose entire life was in a bowel, trying to imagine a ocean.