Ruby on Rails - join
An adhoc and unofficial group for Ruby on Rails (RoR) fans.
Low activity, 2823 members

comp.lang.ruby - join
The Ruby dynamic OO programming language.
High activity, 7261 subscribers, Usenet

ruby-talk-google - join
This is a mirror list of the offical ruby-talk mailing list. It serves as a alternative to the mail<->news gateway (comp.lang.ruby). It exists to provide access to the mailing list via the convenience of Google Groups web-based client.
High activity, 2340 members