JRuby on Matrix
Most of the JRuby team and much of the community hangs out on Matrix, and we welcome everyone to join us!
To join, visit the Matrix #jruby room and select a client that suits you. The Matrix #jruby logs are also publically readable.
Many of the core JRuby committers also hang out on Gitter. The Matrix room also bridges to the #jruby channel on Freenode IRC.