It’s just data

JVM futures

Charles Oliver: Once we’ve solved JRuby’s issues, why not find a way to raise all ships? Support for invokedynamic, open classes, and closures at the VM level? Hooks for code generation, alternative typing systems, and deeper threading, IO, and memory integration? Seamless cross-app connectivity for dynlangs + Java EE with all the tasty agility we’ve come to love?

JPerl6 anyone?  With Classpath+[Kaffe|GCJ|Jikes RVM] or Harmony or Sun’s ongoing process, one significant inhibitor has been/is in the process of being removed.

What impresses me about IronPython is its voluntary compatibility with CPython.  JRuby seems to be heading in the same direction.