I try to help improve JBoss whenever my work goals overlap with the goals of JBoss. I also spend a bit of free time helping people get started with JBoss MQ and JMS in particular. I would like any organization or individual who uses JBoss to contribute back to the community, even if it is just answering user questions, submitting comments, or writing bugs.
The JBoss team puts out a great product and has some of the best developers working on it that I have ever seen. And not only do they write good code, they know how to quickly fix bugs, maintain compatibility, band together for a release, and architect improvements.