Despite resembling Twitter so much, Bluesky is set to have some technical features designed to make it very different from Elon Musk’s social media giant. The platform aims to provide a decentralized social network protocol, which is expected to make its user data free from influence by any government or corporation.
Bluesky is built on the AT protocol, a new federated social network that integrates ideas from the latest decentralized technologies. Originally known as the authenticated transfer protocol, or ADX, the AT protocol is Bluesky’s main effort to enable a new way for servers to communicate with each other, allowing individuals and businesses to self-host and have multiple websites instead of one.
He seems to be supporting both
Nostr came after BlueSky I think