No, Bluesky is masquerading as an open network, but it is a for-profit business. It is not part of the network of Mastodon and it is not compatible with ActivityPub which is the protocol that makes the Fediverse happen.
Mastodon is developed by an actual non-profit, is genuinely decentralized (not in theory, it IS decentralized, right now) and is of course fully open source.
https://blog.joinmastodon.org/2024/04/mastodon-forms-new-u.s.-non-profit/