Keybase should Integrate a federated IM protocol (eg. email, XMPP, or Matrix) to allow self-hosting, new clients, and inter-operability.

> In Instant Messaging (IM), federated IM networks are those that allow communications across different IM clients and platforms, similar to the way email allows people to communicate regardless of which email client they choose to use.

Keybase is great but one drawback is that it is not federated ie. users cannot host their own (interoperable) servers/networks or build their own clients.

This could be solved by integrating (or inventing) a federated IM protocol.

Examples of existing protocols that could be integrated include email, XMPP ([xmpp.org](https://xmpp.org)), or Matrix ([matrix.org)](https://matrix.org). Alternatively, Keybase could do something crazy like invent a new one!

Interoperability would reduce barriers to adoption, and help to further develop a vibrant Keybase ecosystem.

No implementation files or tests are named. Start by defining the interoperability and self-hosting requirements, then compare the proposed email, XMPP, and Matrix approaches against them. Done would require a decided protocol and an agreed integration scope, not just a protocol suggestion.

Written by the indexing model from the issue text.