as i've said before, quake is still far from being finished and you can take my word on this, there are no betas available, no matter what your /<-rad friends said they found on their 31337 ftp/fsp sites. let me relay a quote of ddt on irc late november '94:
"<dtaylor> lot, wish we had a quake beta."
'nuff said, come back in half a year ;)
john romero himself posted a word of warning to all illegal quake alpha testers:
'it seems you guys have gotten ahold of alpha versions of both out vr quake and neural quake and i have to say i am not happy. it is not the fact that you are using stolen software that bothers me, it is the fact that you are putting your lives at risk. just last week a beta-tester lost 33.3% use of his brain testing quake ii on the intel/RS686 for win '98.june. if you guy really want some quake action i suggest you stick quake, winquake, and powerquake. for all you asking where to get it, it is ftp-able from 127.0.0.1 in the /pub/id/quake/incoming directory.
have fun and see you on the quakeservers!!!'
for that matter, the new .plan at email@example.com is quite obvious as far as far as betas go, as it literally yells at us (caps removed to preserve sanity ;):
'there is no beta version of this out *anywhere* there is nothing for anyone to test right now either we are still very much in development'