Here I would like to tell you about some of the Groovy language support improvements available in IntelliJ IDEA 11.1.
Unused Symbol Highlighting
If a class, method or property is unused even if it is in fact public, you may notice it immediately with new unused symbol highlighting feature.
Introduce Parameter Refactoring
Introduce Parameter refactoring has now become more powerful. Just select a couple of statements, press Ctrl+P, and it will create a closure parameter for you.
Ever dreamed of quickly evaluating some code against your project without wasting time to start debugger? Now it is possible with Tools | Groovy Shell. It works even in pure Java projects without Groovy libraries.
Mutable State Highlighning
As you may know mutable state is always harder to manage than immutable. That’s why I like to have it as noticeable as possible. In Java I customize highlighting so that reassigned local variables are highlighted in a way different from assigned only once. Now you can do the same in Groovy Colors & Fonts settings.
And of course you may already know about Chained Call Completion posted before.