I run OpenFire (https://www.igniterealtime.org/projects/openfire/) as my server. Upgrades are easy, and I like the 2000-era interface as it doesn't take up much room, but if I was starting from scratch again, maybe I would try a different server, as the way it deals with Lets Encrypt certs is a bit annoying when it's time to renew - this could be user error, but it's not obvious.

ejabberd having it's built-in "certbot" equivalent sounds great!

I use Monocles (Android) and Dino (Linux) clients, and it's pretty stable. Monocles also allows some server commands from the client, which is pretty cool. Sorting out TURN was a faff, but it doesn't help that my server is behind 1:1 NAT I guess :/

Still, now that is sorted, it's great :) I just need to find out a way of enticing my friends to use this instead of WhatsApp etc