That's why I highlighted the platform strengths -- what others platforms can reasonably compete?
That said, you can use these tools as complete applications without actually dipping your toes into Java (or even the JVM, other than running it). If you do want to write code directly against them, the choices (of which I'm sure you'll well aware) range from Clojure to Scala to Java to JRuby.
Scala is one ugly duck, but personally I find it to be a sufficient language for writing JVM-based code without losing my lunch.
That said, you can use these tools as complete applications without actually dipping your toes into Java (or even the JVM, other than running it). If you do want to write code directly against them, the choices (of which I'm sure you'll well aware) range from Clojure to Scala to Java to JRuby.
Scala is one ugly duck, but personally I find it to be a sufficient language for writing JVM-based code without losing my lunch.