In the last month or so there has been significant developments in the JEE6 space which gives some choice and some confidence to JEE 6 developers.
Glassfish 3.1.1 has been released
With literally hundreds of bugs fixed GlassFish 3.1.1 provides a full JEE6 compliant app server and supports Java 7 already! Glassfish is the JEE 6 reference implementation so has supported EE6 for a long time but the last couple of upgrades have seen clustering arrive and now a whole load of much needed bug fixes.
One thing about the GlassFish model I like is that Oracle release the supported version at exactly the same time as the open source version. This means you can develop knowing that when you go live you can decide whether you want to take Oracle's Premium support without compatibility worries. For added value you can also take one of C2B2's Managed Service options to give you local support for application production issues backed up by Oracle for product issues.
JBoss 7 also arrived this month.
This is the community release of the latest JBoss application server. JBoss 7 is JEE 6 Web Profile compliant so as long as you don't use features not in the web profile your applications should deploy. JBoss 7 is a complete rewrite and rearchitecture of the core application server so looks NOTHING like JBoss 6 or 5. JBoss 7 starts extremely quickly due to lazy loading of many modules. 7 also introduces a domain model for configurations of multiple servers, similar to other application servers. This will help management of larger operational systems.
The RedHat supported EAP 6 version of JBoss will be probably be based of 7.1 so JBoss people thinking of experimenting with JEE6 functionality should really skip the JBoss 6 community release and start messing around with 7. No firm dates for EAP 6 are around so my guess is first half of 2012 but don't quote me on that.
TomEE is also looking interesting
TomEE is the apache project building a JEE 6 web profile compliant container from Tomcat and OpenEJB along with OpenJPA and MyFaces and some Geronimo modules to fill in.
This is a very interesting looking alternative to what is becoming a pretty narrow field of JEE6 application servers.
If we also go slightly back in time.
WebSphere 8 was released with JEE 6 support.
Also IBM released WebSphere 8 as a JEE 6 compliant application server. What is remarkable is that IBM beat WebLogic and JBoss to JEE6 compliance. That's a big change from the old days!
So to sum up this summer we have seen a number of major JEE6 releases with the big guns rolling out and improving their JEE6 offerings.