About 3.5 years ago #dino_im announced that it supports calls and conference calls: https://dino.im/blog/2022/02/dino-0.3-release/

I never used the conferences feature. But this evening I will give it a try. I am a bit excited if this will work out and how the user experience is. #xmpp

Dino 0.3 Release - Dino. Communicating happiness.

A privacy-friendly messaging app for the desktop. It uses the XMPP protocol and provides a clean UI with modern features.

@eversten And ?
@crw We tested #dinoim conferences with 3 people and it worked quite good. CPU usage was very high so the video of one person started to lag after a while (probably because of temperature cpu frequency reduction).
One UX issue: When adding and person to call you do not get a feedback. You click the button and wait if someone joins or not.
@eversten @crw Did you try to also join from Movim? It should be fully compatible.
@kris @crw
Two people used #movim. We managed 1:1 calls between #dinoim and movim but the group call did not work
We had no time to investigate further but we will try it again in a few days, I guess.
We were quite happy that the dinoim conference worked out without any problems.