One major benefit of JRuby is the ability to import Java classes and use them as if they were POROs (Plain Old Ruby Objects). This feature makes Java fun again. You can pull in legacy code and sculpt an API which fits nicely into your Ruby code. You can even access novel and unrivaled Java libraries to do something not currently possible in the Ruby world. This video shows basics of interacting with Java classes from within Ruby, point out Gotchas and gives style hints to make Java APIs fit better into the Ruby way.
Video Producer: JRuby Conference