I am currently working on a mozilla - iax - xmpp combination to work as a front-end for a BPO.
I managed to get the libraries from the following sites
for the mozilla-iax : http://moziax.mozdev.org
and for the xmpp: dev.hyperstruct.net/xmpp4moz
I think I have to rework everything on the front-end using base materials because I have not succeeded in combining the two entities.
Will give update tomorrow.
may the source be with you