The ideas/promises of both protocols are roughly the same (more than a decade apart), but there's major differences in the approach. We have a summary list of p

The ideas/promises of both protocols are roughly the same (more than a decade apart), but there's major differences in the approach. We have a summary list of pros & cons here: https://joinjabber.org/faqs/advanced/#faq-advanced-matrix https://joinjabber.org/faqs/advanced/#faq-advanced-matrix Let us know if something is missing or not clear in there. I would probably add to that that Jabber/XMPP has several producion-grade free-software server implementations (ejabberd/prosody/tigase, maybe metronome?) whereas matrix has only one (dendrite/conduit are still experimental although they made great progress). Likewise, Matrix only has one reference client implementing all features. In both cases, the reference implementation is bloated and not compatible with low-end/second-hand hardware which is very popular in the Jabber/XMPP ecosystem. I expect the situation to keep steadily improving on both sides, or to quote our FAQ: > As you can see, both protocols have their strengths and weaknesses, but they still operate on similar principles. In theory, it would have been possible (and easier) to build the matrix protocol on top of XMPP to avoid fragmenting the ecosystem. Why this was not done is a good question, but the fact is we now have two protocols/ecosystems with similar goals, and we should try to dismantle our egos and work for interoperability, for the benefit of end-users. However, if your goal is censorship-resilience (not privacy) against state actors, then i would strongly recommend to use Matrix instead of Jabber/XMPP because decentralized rooms are tailored to that threat model.