AMQP, XMPP

Stefan Tilkov suggests...

Personally, I see AMQP on the one side and AtomPub/XMPP on the other side of a fence — AMQP internally, addressing the same problem domain as current, proprietary queueing solutions, and AtomPub and XMPP over the Internet.

I'd like to understand more about his reasoning.

What would be the drivers for this dichotomy? Why are two different messaging systems necessary? What would limit AMQP from being used on the internet scale? What would limit XMPP from being used on the intranet scale?

Without some reasoning behind this dichotomy, it just feels to much like the old WS-* on the intranet, HTTP on the internet. I don't recall seeing a sufficient rationale for that.

Now it seems fairly clear that HTTP fits well on both scales, no?

So is HTTP sufficient for all kinds of "message transfer"? HTTP and XMPP? HTTP, XMPP, and AMQP? Or... how many kinds of messaging are enough?

As an aside, our viking friend suggests Apache can go beyond the traditional as well. I think we have a lot to learn still about how simple the enterprise can eventually be.