Four languages which together represent ""
         Clojure, Groovy, JRuby, and Scala. 
Stuart Halloway has explored and compared all these four most interesting new JVM languages.               
Each of these languages aims to greatly simplify writing code for the JVM, and all of them succeed in this mission.

Clojure is a Lisp. 
Groovy is the "almost Java" choice. 
JRuby has the beauty of Ruby, and the mindshare of Rails. 
Scala, unlike the others, brings the notion that we need more static typing.

Read about them in