Earlier quoted context omitted.
> Some sort of open protocol. XMPP seems to be rather dead, for various reasons, and no real contender for a replacement has sprung up. I guess there always is, and always will be IRC…
I use XMPP every day. All my friends are on XMPP. What makes you think XMPP is dead? What are "various reasons"?
It's a real damn shame because XMPP is pretty awesome. It's open for one, can be made super secure with OTR (client-2-client encrypted chats), has numerous protocols and implementations for stuff as diverse as message archiving, Audio/Video signalling, file transfer, chat (of course), presence and an absolute boat load of other stuff: http://xmpp.org/extensions/index.html.
There are two big issues as far as I can see with XMPP which really hurt it:
1. XMPP was incredibly poor at handling high latency, intermittent network connections (like cellular). Connections would time out, reconnections would take ages and all in all it really hammered battery life. As a consequence mobile app developers moved very quickly onto REST/JSON (yes there was XEP-0198 - Stream Management - but implementations of it were thin on the ground and even then it wasn't perfect).
2. There just isn't any interest amongst new developers or newer projects at least in an XML based chat protocol when REST/JSON is so attractive. Anyone who has had to write a god damned XML parser knows what I'm talking about.
Things are a whole lot better now. XMPP has fixed a lot of session and battery life issues since then but to be honest I'm just not feeling it when I go to XMPP meetups. Feel like I'm attending a wake for an old friend and it really is sad because if there was ever gonna be one protocol to rule them all XMPP was far and away the best candidate.
Who knows, a couple years from now large companies and governments might finally wake up to the fact that they have 100 different sucky (probably) REST based APIs amongst all their apps which are not remotely compatible and offer poor archiving and retrieval (like they did in the 90s when they forced Microsoft to open up their Office document format). XMPP might come to the fore again then (wouldn't put money on it though). More likely something similar (and not XML based) will take its place.
It's anyone's guess really, suffice to say the present situation does feel like a complete and utter mess and will really start biting us in the ass when compliance asks 'how do I archive/retrieve this pot pourri of data'.