Using XMPP for instant messaging is really great but if you are looking for more and want to use something federates just like XMPP you probably will stumble upon Mastodon.
Please do not get me wrong, pimux.de will stay as XMPP server but a few days ago I set up a Mastodon server at toot.fan. I waited a few days to open registration to make sure everything is working fine and the backups running without any error.
Feel free to sign up! toot.fan