You’re probably going to end up on Jitsi meet, but I’m also going to drop a recommendation for bigbluebutton.

I recently noticed that it was integrated into the open source Learning-Management-System Canvas, which every school I have gone to so far uses.

Although bigbluebutton doesn’t seem to explicitly support e2ee (but maybe this counts for something), if you are already using Canvas, BigBlueButton definitely worth looking at.

I really, really wish people at my school would use the integrated bigbluebutton instead of using zoom, especially given I’ve seen people occasionally have issues with authentication for zoom, but all of that stuff is handled with bigbluebutton because it’s fully browser based and integrated into Canvas.

It’s already been mentioned, but I’ll throw in for Jitsi. I believe it can also be self-hosted.

Matrix Jitsi

Jitsi, Nextcloud Talk and Signal are all very good options (if you don’t need screenshare with desktop sound (e.g. a watching a tutorial video with sound), I haven’t found a FOSS solution that can do that - though tbh it’s been a while since I tried it with something other than Signal)

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never heard of jitsi, but looks pretty legit from what you shared!

We used Jitsi quite a bit during Covid, I was very happy with it, and I don’t remember any complaints from other people.

Maybe Signal since they have group call links now ?

I personally haven’t used it yet but I believe you can do all this with Matrix (choose your client - probably Element).

Jami is also an option