> Why do you say that the author knows what he's doing?

Jeremie Miller wrote a popular open source IM server and created a specification for the protocol which has been widely implemented in several different languages (Erlang, C, Python to name a few) for both client and server.

Many of the functions solved by XMPP (instant messaging, presence, federation) fit nicely into the distributed social network problem domain.

So that's why I have confidence that he knows what he's doing. Nits like "I don't like different XML namespaces" more or less miss the forest for the trees.