The Apache ActiveMQ message broker is an open source implementation of the Java Message Service spec. It makes for a reliable hub in any message-oriented enterprise application and integrates beautifully with Java EE containers, ESBs, and other JMS providers.
ActiveMQ in Action is all you'll need to master ActiveMQ. It starts from the anatomy of a JMS message and moves quickly through connectors, message persistence, authentication, and authorization. By following a running example (a stock portfolio app), you'll pick up the best practices distilled by the authors from their long and deep involvement with this technology.