Java EE (Java Enterprise Edition) General Discussion

We're looking for a way to monitor a 'topic' from a web-page.

We're currently thinking about using Javascript from within a HTML frame to refresh itself with output collected from a topicServlet. I would assume that the topicServlet would subscribe to specific JMS topics and cache the events so that when the browser 'polls' for updates it's able to send out last 100 postings.

a) Is this a common implementation or is there another way to do this?
b) Can we use the JMS reference implementation to accomplish this or do we need to consider a comercial implementation of JMS, like JMQ?
c) If we decided to do use applets, could we 'push' events out to the browser?

Please any help on this appreciated.

Thanks in advance,
Joe