Jabber is actually a relatively light weight messaging and presence protocol, in compairison to the new RFCs that cover messaging and presence. However, it is also either poorly documented or poorly understood, and the use of xml appears to be much more trouble than it is worth.
It is difficult to compare the Jabber community to the OACS. Maybe you could compare it to something like Mozilla. I don't know for sure, but I bet there are not a bunch of consulting companies based on Mozilla.
