RIP, XMPP + federation (fb messenger, slack, whatsapp, hangouts/gchat, and more used to be accessible through a single client. That said, I recall federation w

RIP, XMPP + federation (fb messenger, slack, whatsapp, hangouts/gchat, and more used to be accessible through a single client. That said, I recall federation was mostly unsupported by the various hosts, so you still needed to be logged in to each service.)