The JSRs that define the JMX API are being updated through the Java Community Process. JSR 3, which defines the original JMX API, is undergoing its third Maintenance Review. JSR 160, which defines the JMX Remote API, is undergoing its first Maintenance Review.
So what's that all about? The situation is that these specs are being updated in Java SE 6, code-named "Mustang". Formal Java Community Process rules mean that we need to conduct this Maintenance Review. Everyone is invited to study the Change Logs (JSR 3, JSR 160) and send comments or corrections to firstname.lastname@example.org. (In fact you should always feel free to send suggestions to that alias, whether or not there is a Maintenance Review in progress.)
If you've been following the changes to the JMX API in Mustang, you won't be seeing anything new here. But you might find it useful to see the detailed list of changes all in one place.
This Maintenance Review will define version 1.3 of the JMX API and of the JMX Remote API. The previous version of the JMX API was version 1.2, so no surprise there. The previous version of the JMX Remote API was version 1.0, but it's jumping to 1.3 to reflect the fact that the distinction between the two APIs is just a historical artifact, and they should really be considered to be the same API.JSR 255 will ultimately merge the two APIs formally, to make JMX API version 2.0.
It's currently planned to have a second pair of Maintenance Reviews later this year that will change some minor details of the APIs. That will define version 1.4 of the two APIs, which will be the version that appears in the final release of Mustang. So version 1.3 will be an ephemeral one, a bit like IPv5.