Looks like Ruby on Rails has inspired a sister-name. This shows that scripting languages are becoming "in" especially when coupled with some kind of "infrastructure" which makes it easier to code in. Here, it looks like Groovy is the dynamic language within a Java framework. So is Java like the "rails" in "Ruby on Rails"?
Link: Oracle gets Groovy with open-source project | CNET News.com.
Oracle said it will participate in Grails, an open-source project that seeks to make Java programmers more productive through a close tie-in to the Groovy scripting language.
Grails is a project to create a development framework, a set of prewritten software components designed to speed Web-application creation using Groovy. The name Grails was inspired by Ruby on Rails, a productivity framework for another language called Ruby.