Damus runs on the Nostr protocol. Check out https://nostr.com/get-started for an intro into Nostr.

Bluesky is runs on a separate protocol, but you’ll have to join a long waitlist for an account.

Nostr is a protocol. Damus is a client that uses the Nostr protocol. Dozens of clients exist. Welcome! 🫂🤙🏻💜