Matrix: a new specification for federated realtime chat

> Yet it remains the *only* option there is if you want an IM solution that doesn't require you to sign your soul (and your messages) over to $BigCorp.

You could hand out accounts to one machine and have everyone use `wall` and `talk` to message each other. You could even get fancy and have people attach to tmux sessions to do group stuff. So, no, XMPP isn't the *only* option. You just need some imagination ;) .