Actually, JRuby is a JVM clone of Ruby. And Ruby on Rails on JRuby is a JVM clone of Rails. I don't know where to start with the differences but Grails is noth

Actually, JRuby is a JVM clone of Ruby. And Ruby on Rails on JRuby is a JVM clone of Rails. I don't know where to start with the differences but Grails is nothing like Rails. The ORM, the naming conventions, configuration, GSPs vs ERB, the way routing works, and pretty much everything else is different. They both use MVC and Grails draws inspiration Rails but is it in no way a clone.