The most surprising this thing about the results was that the JBoss 7 average startup times where extremely fast compared to the previous JBoss versions.
At the beginning we couldn't believe this improvement is for real and assumed that JBoss 7 is an OSGi container. But just a bit later some JBossAS developers commented on the blog entry, that actually JBoss 7 has been completely redesigned for classloading performance.
Andy Miller said:
The startup times really don't have anything do with the OSGi stuff that is in there. It's based on a new services architecture underneath, which can start services and load classes in parallel (there are some JVM limits in class loading that make it serial, but we hope that will disappear), and take advantage of the fact that there are multiple cores on virtually every machine someone would use today.
To learn about the new features in JBoss 7, the highly recommended listening can be found at the JBoss Asylum podcasts page.
Thumbs up for the JBoss engineers, really! At least some AS vendors do care about the developers productivity! :)