Already a decentralized federated protocol · Issue #255 · bluesky-social/atproto...

There are a lot of differing design decisions.

Account portability is a major reason why we chose to build a separate protocol. Signed data repositories and DIDs are both unique to ATP and not terribly easy to retrofit into ActivityPub.

There are smaller things as well: a different viewpoint about how schemas should be handled, a preference for domain usernames over AP’s double-@ email usernames, and the goal of having large scale search and discovery (rather than the hashtag style of discovery that AP favors).

Meta:

The AP community has always been somewhat suspicious of Bluesky, for reasons that are understandable. AP’s community is volunteer driven and the users joined to escape Twitter. So, here we come, a startup funded by Twitter, with strong opinions on how the tech should be done. I’ve heard concerns that we’d “embrace, extend, & extinguish.” I’ve heard concerns that we’d force through changes that people don’t want by dint of being a funded company. You can criticize us for going a different direction but I think it’d have been a difficult collaboration if we chose to use AP, especially since we weren’t willing to compromise on some of the decisions above.