In this chapter, we covered JMS in detail. We talked a bit about messaging. We also provided a brief overview of the JMS and MDB programming models. We talked about the various JMS providers supported by WAS, both internal and external. We also showed how WebSphere Application Server works with various JMS providers. Specifically, we focused on the embedded JMS server and WebSphere MQ. Finally, we configured the server and deployed the Personal Trade System with added use cases that used embedded messaging. In the next chapter, we will look at some other resources supported by WebSphere Application Server, such as JavaMail and URL Resources.