Today's multi-language JDK
By dannycoward on Mar 10, 2009
It can be too easy as you reach out for the next thing, to forget what's already in your hand.
In fact, the recently released Groovy 1.6, which includes a number of new language features (like optional returns from if/then and try/catch blocks, multiple assignments) as well as some handy peformance improvements, includes this pluggability layer into the JDK built-in.
And Python 3.0 has been turning the handle on new features. It's one of the 3 official languages of Google (the language of the Google App Engine, for example), and even runs in your hand today, on certain mobile phones.
As can Ruby, via the JRuby (Ruby on Java) project. Ruby's latest feature release (1.9) in January is one of the big ticket items for the next JRuby release.