@
blaine @
Evan Prodromou @
Erin Kissane Depends on what you want.
If you're looking for something like WhatsApp or Signal, that'd be the #
Matrix and #
XMPP protocols. Both are free and open standards, both are old and mature enough to come with their own well-established mobile apps if you need one, and both have moderated public and private multi-user chats amongst their features.
If you're looking for something that's part of the #
Fediverse, then #
Friendica, #
Hubzilla and #
Streams offer not only public groups/forums, but also private ones. And when I say "private", I mean it because they aren't bound to the limitations of what #
ActivityPub would allow them to do server-side. At the same time, they're federated with #
Mastodon etc.