Matrix seems like a decent enough open protocol for a Slack replacement, with XMPP/IRC/IRCv3 being more useful for bare-bones chat transport.
This Chatto thing unfortunately uses a Protobuf custom API and is explicitly anti-compatibility with other systems. The lack of interoperability may end up killing it, unless the experience is much better than everything else.
This Chatto thing unfortunately uses a Protobuf custom API and is explicitly anti-compatibility with other systems. The lack of interoperability may end up killing it, unless the experience is much better than everything else.