matrix-doc VS Mumble

Group voice and video calls are not E2EE, and use Jitsi, but this is expected to change with Native Group VoIP Signalling.

DMs in Matrix are always E2EE, and MSC3401: Native Group VoIP Signalling means there should be E2EE in group calls.

From my perspective, the really exciting thing about this that it works equally well in mobile web browsers as well as desktop web - clicking on a link on Mobile Safari should Do The Right Thing without having to install anything.

Moreover, because it's built on Matrix, MSC3401 (https://github.com/matrix-org/matrix-doc/blob/matthew/group-...) means that we'll finally have decentralised cascading video/voice conferences once the SFU (selective forwarding unit) component is added into the mix. So, for instance, users on the same homeserver will get their video feeds relayed locally with minimal latency... and then users on another remote homeserver will also get mixed locally with minimal latency, trunking the two together. If the link dies or one homeserver dies, the conference will keep going - i.e. precisely the same semantics as normal Matrix.

What metadata does Matrix protect? Encrypted state events still aren't a thing for example https://github.com/matrix-org/matrix-doc/pull/3414 This means that server admins know what groups a given account is a member of, private or not, and they also have a general idea of what the topic of said groups are, even if they're encrypted. This would be a problem for groups about sensitive personal medical issues, like a private HIV survivors or Alcoholics Anonymous group.

The protocol itself is flexible and can be changed through spec change proposals on their Github. They're currently working on implementing threads, and they recently implemented spaces, which functionally combine the concept of Discord servers and server folders. They can also be nested.

At the moment this only works with Jitsi. It will be implementet soon with MSC3401

Something we're trying to do about this on the Matrix side is MSC2716 (https://github.com/matrix-org/matrix-doc/blob/matthew/msc271...) - the ability to import archives of existing content into Matrix, and thus 'lock it open' and decentralise it for posterity: as long as one of the servers participating in that room stays alive (and the room is set up with infinite data retention, obviously) then the conversation will live on forever. (That MSC is also well worth a look for those interested in how Matrix works under the hood; MSC2716 was a surprisingly tricky problem to solve but it's basically finished now!).

Our first step will be to import all of Gitter's archives into Matrix - but we're then planning to add MSC2716 to all the existing Matrix bridges so that folks can use it to liberate chat history from Discord and Slack if desired, and avoid it getting paywalled/siloed/lost/held-hostage forever. We're also expecting to do USENET, mailing lists, forums, public IRC channels which have explicitly opted into logging... and generally archive as much possible in an open decentralised fashion, and ensure that gatekeepers can't lock up and blackhole info going forwards. After all, information longs to be free :)

by 'broken links' i guess you mean https://github.com/matrix-org/matrix-doc/issues/3628? it's a bug on the new spec website; we're working on it.

I think Sonobus is overkill. I suggest you look at a couple of relatively old-school gamer voice chat tools - Mumble or Teamspeak. Mumble is open-source and the connection is always encrypted, Teamspeak is commercial but the free tier should be fine for you - but you have to make sure to manually turn encryption on yourself. It has been a long time since I used either, so I don't know which is easier. Both of them require you to run their matching server software.

Mumble's latency is unbeatable imo, it's basically their main focus and shows.

The sticking point for me is the lack of persistent messages, something the devs strangely think is a privacy plus. Issue open since 2016: https://github.com/mumble-voip/mumble/issues/2560

If you drop out for a minute you won't have access to anything that was posted in chat, which makes it useless for anything other than voice only comms, that might suit some business purposes but I've always needed to post links or screenshots in chat during meetings.

There's any number of alternative chat applications available, like Element, Mumble, Teamspeak etc.

Mumble?

I think Mumble might fit what you're looking for. It's been a very long time since I've used it, but it seems to still exist: https://www.mumble.info/ - I've used previously for exactly what you're describing, events with lots of crew dispersed around and no budget for radios. I had it installed on an AP running OpenWRT so it was just a case of plugging that in and getting people to install the app and connect to it.

Along with the options already mentioned, if you're not into TeamSpeak, there is an open source alternative called Mumble which operates in the same manner. No internet required, and is supported on multiple platforms.