You could use JRuby and Rails if you need the JVM. Groovy's OK for wraparounds testing and/or running Java classes, what it was originally intended for, bringi

You could use JRuby and Rails if you need the JVM. Groovy's OK for wraparounds testing and/or running Java classes, what it was originally intended for, bringing closures and terser list/map syntax (altho JRuby et al have those too). It's all rather slooooow though. Grails uses Groovy's MOP which was added later, but I don't use them much. I toyed with Groovy's interceptors and categories when they were added, even wrote notes on them, but they broke in the upgrade from 1.5 to 1.6. There's a lot of such cruft in Groovy which just lapses from version to version through lack of use and support. They brought in AST transforms to get programmers to extend Groovy's functionality, but when they do, the Groovy managers wil swipe the code and pass it off as their own in the next version of Groovy (e.g. Groovy++ written by Alex Tkachman was cloned as the static compilation in Groovy 2.0 and the static traits in the upcoming Groovy 2.2). tldr... Use grOOvy for quickies handling Java classes, and for Grails where it's required, but look at a serious programming language for anything larger.