Introducing a new JVM programming language into an established enterprise environment

Question

Imagine that your current workplace is a Java shop. There is a lot of built-up knowledge about the Java language and there is a comprehensive build and deployment process in place to handle everything in a smooth and Agile manner.

One day, a project comes along that just screams out to be written in, say, Ruby. Only the senior developers have any clue about Ruby but there's a general notion that since JRuby exists for the JVM then existing infrastructure could continue to be used and supported. Also, JRuby could show the way to a better way of implementing the current applications with less code so this could represent an ongoing migration.

Remember that JRuby is just an example, it could equally be Clojure or Groovy or whatever else runs on the JVM.

The question is how would you go about introducing this kind of change - if at all?