In case you didn't know:

Jabber and related XMPP are the protocols behind a wide range of consumer, business, and military communications. It allows chat, instant messaging, phone, files, basically any internet communications.

Its like a non proprietary Discord.

There are a multitude of Jabber (XMPP) servers, its all open source, readily secured, and one can easily set up their own.

A lot of business and politics goes on these networks, and they should be a first consideration for network survivability and political discussion.