I'm currently learning Groovy, a JCP accepted scripting language for the JVM, and potentially the official one in the upcoming 1.6 release of the Java Language Specification. It's a dynamic AND statically typed language, strictly integrated with the Java language and binary compatible with the byte-code of the JVM. Though it may seem "yet another scripting language for the JVM", it's quite different from projects like JRuby, Jython, Rhino or similar projects. In fact it has some feature which can make it a powerful competitor for other dynamic languages.