Most of the presentation slides from JBossWorld can now be found online at JBoss World Recap. There is a lot of valuable information in many of those presentation, so I would highly recommend everyone to have a look at the presentations corresponding to their subjects of interest.

I did a presentation as well, focused around the 3.x/4.x JBoss MicroContainer, under the title "Never Write A main() Again!". The original intension was to show that in most cases in which a server application needs to be created, whether it is EJB based or not, it makes perfect sense to reuse the JBoss MicroContainer (for example, start off with the "minimal" configuration) and just add your own extension in the form of MBean Services, rather than starting from scratch.

The same is true for your normal J2EE application, where you just want to add functionality to the server that is difficult to write using the "standard" J2EE tools (for example, a lightweight adapter to an external system, without the burden of creating a JCA resource).

In any case, the benefit is a very high degree of reusability of components that are really well tested and difficult to write (e.g. the unified classloading mechanism of JBoss that makes hot-deployment possible).

I've been doing MBean services with JBoss for almost 4 years now and while the whole idea is very neat and simple, it is impressive how few people actually know about the existence of this technology and its many uses. Most developers only get to learn about this in one of the JBoss trainings.

We now see the proliferation of various container-like projects coming about as the new "cool" thing, while it is true that JBoss has been doing this kind of stuff since year 2001.

In any case, I tried to distill in just a few slides the really essential stuff that you need to know in order to write your own MBean. This is not rocket science at all, and I usually need 15-20 minutes to get someone up to speed with writing her own MBeans and start extending JBoss in arbitrary ways. In fact, it is often the case that people, after they write their first MBean and see how easy it is, they want to go about and MBean-ize everything :)

Anyway, I hope you find the presentations useful.