The Server Side is reporting that Geronimo, the little application server that largely couldn't, is struggling to catch up with JBoss, but is falling short largely because of its biggest corporate sponsor: IBM. IBM provides productized versions of Geronimo but they don't bring home the WebSphere revenue bacon (neither do support subscriptions around it), leaving Geronimo's future very much in doubt.
Apparently, getting one's sponsorship from a company with a competing, proprietary product to protect is not a winning strategy:
Geronimo is much like Eclipse: not formally controlled by IBM, but since most of Geronimo's core committers are employed by Big Blue, control more or less belongs in IBM's hands.
Innovation for Geronimo is being driven by two factors: one is IBM's apparent decision to not invest in architectural resources for Geronimo, and the other is IBM's protection of the WebSphere brand.
IBM employs a majority of active committers, which puts Geronimo in an unhealthy dependent position to IBM. It means that when IBM decides to scale down its involvement (as it reportedly has), Geronimo suffers much more than it would if it were a true community project. For Geronimo and other open-source communities, it's important to remember that reliance on your competition to feed you is bad practice. (Novell, you listening?)
JBoss is innovating. (More importantly, JBoss' customers are innovating with it.) WebSphere's innovative days are largely past. (More importantly, its proprietary nature largely inhibits customer innovation with it.) Perhaps this will mean that IBM will eventually route resources back to Geronimo to make it a viable competitor to JBoss. But while IBM has so much money to protect in WebSphere, I just can't see this happening.
It's a difficult quandary for proprietary companies. They may want to open up, but their existing revenue streams prevent it. Hence, for the moment, being IBM's baby may well be worse than being an orphan.