A minor update of the major release JBoss AS 5.0, which was in development for at least three years and was built on top of a new JBoss microcontainer. JBoss AS 5.1 contains a preview of some elements from the Java EE 6 specification.
The Java EE profile is only partially implemented: It includes MDBs, but listening to JMS destinations is not supported. It is, however, certified for the Web Profile. The software code has been completely rewritten for JBoss AS 7. Major changes visible to the user are the inability to define resources like JMS destinations and datasources inside archives (war/ear), the way datasources are defined, a much smaller size (less than half of JBoss AS 6) and a 10-fold reduction in startup time.
16 February 2012
Red Hat implemented the remaining parts of the EE spec, and this version was certified for the EE full profile.
JBoss itself is open source, but Red Hat charges to provide a support subscription for JBoss Enterprise Middleware. Before November 2010 JBoss was licensed as annual subscription in bundles of 4 and 32 CPU sockets. As of November 2010 the licensing changed and all cores on the system are now counted. The core bundles licensing is available for 16 and 64 cores.