This is by and large a red-herring. Unless your Ruby app is leveraging JRuby's integration with Java... you can just take your Ruby app, fire it up on Rubinius

This is by and large a red-herring. Unless your Ruby app is leveraging JRuby's integration with Java... you can just take your Ruby app, fire it up on Rubinius or MRI, and you're no worse for wear.