I've worked on XMPP. Google talk / now hangouts once was an XMPP pusher. XMPP is decentralized. As with mail servers you can advertise your own XMPP servers, s

I've worked on XMPP. Google talk / now hangouts once was an XMPP pusher. XMPP is decentralized. As with mail servers you can advertise your own XMPP servers, see https://wiki.xmpp.org/web/SRV_Records https://wiki.xmpp.org/web/SRV_Records , you can even publish a per-user DNS record with an OTR key. I shut down my XMPP endpoint a few monthes ago because Google had stopped supporting XMPP bridging to hangouts. Now that everybody uses hangouts (coders) or slack (teams/corporates) or whatsapp/messenger/skype (everyone else) there is no incentive to support it anymore (I speak now only IRC with coders) They gave their support and a lot of traction to the protocol, and removed it on a second step (once advocates of XMPP, _yes, like me_ said to everyone, "yes you should prefer gmail+talk, they are supporting open standards") Looks like an approaching-with-good-intentions and then disrupting strategy to me. Even if you disagree on the responsibility of XMPP rise and fall, they are the bull in a china shop : don't drink the kool aid, you'll end up broken.