Try Matrix[1]. It's a protocol specification with multiple open-source implementations. It has federation so that you can choose which server to use (or run you

Try Matrix[1]. It's a protocol specification with multiple open-source implementations. It has federation so that you can choose which server to use (or run your own) and still communicate with everyone else. It has end-to-end encryption (although at the moment it only works in one client, but it's coming along). [1] https://matrix.org/ https://matrix.org/