It's not just Java and Groovy. I've managed to write a "Hello World" app using 6 different JVM languages:
https://bitbucket.org/puffnfresh/hello-jvm/src/f78a6a2312ae/...
Interoperability is actually very nice for most languages.
https://bitbucket.org/puffnfresh/hello-jvm/src/f78a6a2312ae/...
Interoperability is actually very nice for most languages.
edit: Maybe I've misinterpreted the headline to mean more than it should.
And of course Python and Ruby do it differently, having J- and Iron- implementations, each at different versions to the primary implement and each other.
i.e., they're all labelled "java.next()"