Yeah, Michael Abrash is really a legend. He went a different way than Carmack ( he actually works at Microsoft now, and was affiliated with the XBox project ) , though.
Also, I beliebe Carmack might have had more to do with Quake than Abrash. Abrash actually wasn't there in the early stages of the project, and his main job was optimizing and stuff - although he sure owns at that!
Amusingly, Carmack actually learnt his initial VGA stuff in Abrash articles, hehe