It will be open source, end to end encrypted using Signal’s double ratchet encryption protocol, and he plans to make it easy for fediverse platforms to integrate it. The beta will release later this month.
He’s also the creator of https://fedidb.org btw
While no details are clear, it’ll definitely not be this. Matrix has it’s own implementation which isn’t compatible with signal (megolm or something like that), and I really don’t think dansup will be making it matrix compatible. It’ll probably be its own thing.
Oh, that’s a shame. It’s one of the bummers of instant messaging, everything seems to be incompatible with everything