I’m having lots of fun with JRuby lately. 1.4.0 just came out.

reasons to try it

  • if I ever have to break out of Ruby for performance, I want to breakout to Java, not C.
  • the install is trivial (on almost all platforms)
  • threads work
  • you get to run rails/Sinatra/Rack apps on Glassfish
  • the JVM has instrumentation/debugging support like you wouldn’t believe
  • it’s another good way to smuggle Ruby into the enterprise
  • the only way to run Ruby on GAE

Anyway, here’s the install.


curl http://jruby.kenai.com/downloads/1.4.0/jruby-bin-1.4.0.tar.gz | tar xzf -
Applications $ cd jruby-1.4.0/
jruby-1.4.0 $ ./bin/jirb
irb(main):001:0> RUBY_PLATFORM
=> "java"
irb(main):002:0> "t00w".reverse
=> "w00t"
irb(main):003:0> quit