Since Google App Engine will soon full support Java: Would it be possible to run Ruby on Rails on Google App Engine? Or the limitations imposed by the AppEngine runtime will affect the JRuby impl...

I have been hacking with Ruby from time to time, but I haven't done anything big or multithreaded with it. I have heard that MRI only supports green threads and JRuby supports native threads via JV...

Why would I choose to use Groovy when I could use Jython or Jruby? Does the language provide any inherent advantages to make up for the fact that Jython and Jruby skills are applicable to their par...