So far, we've been discussing the DLR and its applications. In this chapter, we will look at the framework in the Java world that's equivalent to the DLR. We will see how that Java framework facilitates running dynamic language code on the Java virtual machine, how to host dynamic languages in a Java program, and what kind of language interoperability the framework supports. When appropriate, we'll compare the Java framework and the DLR. If you have a need to write Java programs that use dynamic languages, this chapter will help you quickly get up to speed by leveraging what you've learned so far.