The #ActivityPub gateway is a server component that can work with any #XMPP server or client, not only #Libervia .
About the status, it's working. I have 2 more things to do before the release:
- HTTP signature for GET requests (it's only done for POST requests right now), which will make it compatible with secure mode of other implementations.
- Use per-user encryption keys. For now it's one for the whole instance.
Both things are easy to do, I just need some time.