Some dude's painstakingly coded replacement pixel shaders for the entirety of S.T.A.L.K.E.R. Apparently it improves the buggy-but-brilliant FPS's both performance and appearance. So well, in fact, that it's to be a part of the next official patch. Clicky the below to embiggen and admire this fan-made handiwork.
I've always maintained that, as well as porn and pictures of cats, the entire internet is built upon the kindness of strangers - strangers who, for free, make mods, and fixes, even those who risk jailtime by sharing forgotten gaming wonders with people they don't know. It's great to see one of those kind strangers receiving powerful thanks - hopefully it's the start of a long and lucrative career in games development for this JJ Walker fellow.