All the following examples can be "run" either from the command line, or by using jirb_swing, the Swing-based IRB console that comes with JRuby. You can start jirb_swing like $ jruby -S jirb_swing. A special require 'java' directive in your file will give you access to any bundled Java libraries (classes within your java class path). If you need to access Java libraries not contained with the Java