nah, the company that makes quake graciously provides a linux installer. the game itself isn't opensource.
as for the PC-mac, i prefer PC's as i can pick and choose whatever configuration i want. also, i've never had much luck with macs. either the OS doesn't let me do something or it crashes at the wrong moment.(working with them in school was hell, 2/3 saves it crashed. rewrote a LOT of work) then again, windows can be just as bad and worse.
you can install linux on either platform so its not all bad.