Matrix.org

Matrix is a decentralized communication protocol, similarly to XMPP. Although you can use a client and server of your choosing, as of writing there are fewer Matrix servers compared to XMPP which means less variety to choose from. The Matrix clients on the other hand are more modern, usable, and full-featured by default compared to most XMPP clients. There are several clients to choose from, the main one is Element which works both on desktop or as a web client most Matrix servers run their own instance of. Alternative clients are Revolt which is mostly just a wrapper for Element, Nheko, Fractal, and there is also a plugin for WeeChat (beta).

Matrix Servers

A list of servers can be found here and here.

Some notes on a selection of servers:

• Matrix Org - Official server of the Matrix Foundation, you might want to avoid it due to its political bias.

• Beerfactory No reCaptcha required.

• TeDomum No reCaptcha required.

• FENEAS Registration (as of writing) disabled.

• PrivacyTools Has a CoC.

Ties to Mossad

If it sounds like too good to be true it probably is, being a bit of a centralized botnet Matrix is quite suspect. It indeed is billed as a "private" means of communication, and yet is born out of a project by Amdocs, an Israeli company based in (In)TelAviv (Intel) with ties to the Mossad.

For a bit on their history, it is quite the read. And if you do doubt that, here is more info about their ties.

XMPP doesn't suffer from these problems and is an IETF standard as opposed to the pile of webshit that Matrix is.