We switched from Slack to Mattermost internally, and while setting it up I noticed Jitsi integration offered. I've been really impressed by it, and we're working to move most meetings to it. Some teams are still using Zoom, but I don't think that's going to last very long!

My Brazilian Jiujitsu academy is trying it out, too, for virtual classes during shutdown. We just held the first today, and a bunch of non-technical parents were able to get things set up for their kids so that we could all attend a class together. It worked quite well. Given the price, it's a really impressive piece of software.