If you're into retro-computing and unix, there's also http://www.sdf.org http://www.sdf.org and http://tilde.club http://tilde.club (but, as I understand, their

If you're into retro-computing and unix, there's also http://www.sdf.org http://www.sdf.org and http://tilde.club http://tilde.club (but, as I understand, their membeship waiting list is endless at this point).