RE: https://nerdculture.de/@anon_4601/116131664815678835

Well, there's XMPP - it's federated, nowadays all server and clients are e2ee by default, it has less metadata issues than Matrix because it just passes messages, like mail does (Matrix behaves like a network-replicated database)

@lafleur
Thank you! I agree with your opinion on XMPP vs Matrix.
The problem for me is not technical but legal: the XSF (which manages the protocol) is based in Denver, USA.
With the list, we are trying to create an ecosystem completely detached from American jurisdiction for reasons of European digital sovereignty, so XMPP does not meet the criteria.
Even though it is an excellent protocol, with immense regret we have to say no.
@anon_4601 okay, I've been giving this some thought - it appears the XMPP protocol is licensed with the apache2 license, which means that a) we can build software and infrastructure upon it without any obligations towards the creators besides mentioning them, and b) we can fork the protocol itself anytime