> Signal 501c3 is a centralized service. XMPP and Matrix are decentralized/federated. SimpleX is distributed.

Session is a decentralized Signal fork that creates the account on the device without associating it with a phone number.

https://getsession.org/

See also maqp2's comment here regarding Simplex:

https://web.archive.org/web/20250302182017/https://reddit.co...

You should definitely avoid Session. While its decentralized nature is a positive, the developers have implemented many features insecurely and have also removed forward secrecy. There are blog posts by a cryptography expert on this topic: https://soatok.blog/2025/01/14/dont-use-session-signal-fork/