What is Groovy anyway?
Groovy is a programming language based on java. Its what happens when you take mix Perl and Java, and sprinkle on some Ruby.
Groovy is weakly typed, unlike java, but shares most of java's syntax (as well as the java virtual machine), but guess what -- you don't need semicolons at the end of the line. You can use pretty much any java class and syntax you want, and that means that any java programmer can learn it quite quickly. Once you get the hang of it you can pound out code pretty quick. (BTW, Groovy is the core language of the Grails web framework.) Groovy comes with a simple editor (the groovy console) , as well as a shell for scripting fun, but for heavy duty programming fun its supported by Eclipse, and NetBeans (which I use) .
You can find plenty more Groovy propaganda (and doc) at the Groovy Hompage
The current version of Groovy can be downloaded for Linux and Windows ( No current OSx support -- whats up with that? I use all three OS's)