Clojure. It's mildly exotic in being Lisp-y and functional, but efficient, clean and solidly supported by the gigabytes of Java library code that's available fo

Clojure. It's mildly exotic in being Lisp-y and functional, but efficient, clean and solidly supported by the gigabytes of Java library code that's available for every purpose and can be smoothly interfaced. Lua. A tiny yet powerful language whose only data structure is the associative table. Can be learned in half a day.