DarkPlaces is how I've been playing Quake for years now but I'm not sure if Quake 1.5 would clash with it, much like how I use Brutal Doom for Doom mostly nowadays and it's hard to go back to vanilla even though vanilla is still good.

Are the two mods compatible with each other?

EDIT: Nevermind, I downloaded it and the Readme says it only works with Darkplaces, so that's good. :)