This is an excellent book for experience java programmers who want to become familiar with Jboss. Each chapter goes throgh the practical application of many jboss features and by the end of this book you will be able to build out youre own Jboss application from beginning to end (Client, EJB and Persistance tiers). It does not however go into any detail on some aspects of jboss that might be useful like explaining the JCA architecture or MBeans in detail. I spent 6 months working in JBoss and this helped me copperfasten my experience on the project and become more familiar with areas that initially had gone over my head. I now have a solid understanding of EJB, JMS, MDB, Hibernate, JAAS, Servlets, ANT, XDoclet and how to apply them. Its the best of whats out there right now.