I just happened to notice at http://www.quakelive.com/#!faq/faq_question_3 that there is some misinformation regarding the system requirements for QL. It states that Windows XP or Vista is required to play which is not true. I am using openSUSE Linux with Firefox version 3.6.17 and I play almost daily (and everything runs great!). It is notable that I actually retrograded my Firefox version when FF4 came out because at the time, it was not compatible with QL (not sure if it is now or not). FF4 sucks anyway compared to 3.6.

There is also no RAM requirement listed on that page so I guess the implication is that you need at least 256MB seeing as how that is the bare minimum that XP will run on. I find it hard to believe you could play smoothly with that much but stranger things have happened I suppose.