I meant a version of the engine just like Darkplaces (which FTE might already offer, I don't know). Now, I've seen that FTE does load custom progs.dat (doesn't need to be qw), but the problem I seem to have with it is that, well, first loading takes forever and then, for odd reasons, the maps I play randomly restart when I play Ultimate Quad Capture. It might be because of some incompatibility between my QC code and the way FTE is coded, though.
I've heard about compatibility with Doom and always thought it was a kind of urban legend
It might sound silly to some, but I think it'd be cool. I mean, there are a bunch of Doom2 maps out there whose architecture, while not being super-complex, is still very nice and some duel packs which could totally fit Quake. But then I do have this ideal vision of a single Quake engine able to read dozens of different map formats, so I'm probably biased 