There are a large number of JMX applications out there. Probably the most common one people will come accross is JBoss. Each component in JBoss is provided as a MBean service, so its not really one big application but numerous applications integrated together via JMX. There is a very good overview of JMX in "JBoss Administration and Development" (which you should be able to find somewhere on JBoss's site) that discusses JMX in light of how it is implemented in JBoss.
According to my understanding JMX API has a bunch of interfaces. Is there an implementation in versions below J2SE 1.5.
I did see in the downloads of SUN JNMX "JMX Reference Implementation" jars. Can these jars be used in real time applications or are they just a reference for those who are implementing the JMX containers?
Weblogic has a built in JMX container, with about 300+ mbeans on start, instrumented to monitor every aspect of the system. This number of mbeans will increase for every session, user, servlet, ejb, etc. that gets added.
JBoss is about the same -- in numbers but different from Weblogic. In fact, JBoss is one big JMX container. The Servlet container, EJB container, etc., are just mbeans running in the JMX container.
Tomcat has about 30 or so mbeans on bootup -- most of them are of a "generic" nature. Not really explaining this one well, except when I was working with it, there wasn't much interesting.
I have Websphere on my work list. And one of these days, I will get a customer that needs it, and I can bump up the priority on working with this one...
Cruise Control also uses JMX for remote administration.
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - Heraclitus