I’ve been running Prosody [0] for many years now. Don’t ask me why I chose it over another server. I used to have a jabber.org account that I used before that, already back when I could use jabber to communicate with gchat and facebook messenger users. Alas, nowadays, it’s just my wife I use it to communicate with :(
Prosody was a breeze to set up and it worked pretty well for me. I set up a simple bot to get notifications on my phone. The whole set up works great until you get to the notifications. Super unreliable. I believe that's an issue of the iOS client I am using.
Prosody is sweet. I forget why I switched over from ejabberd, but it it was quite reliable and had such a huge breadth of extensions it supported. Ejabberd has been intimidating to setup but really wasn't hard, but Prosody was a snap.
[0]: https://prosody.im/