Bluesky, a social network championed by Jack Dorsey, opens for anyone to sign up

Bluesky, a Twitter-like social network championed by Twitter co-founder Jack Dorsey, has emerged from its cocoon and is now allowing anyone to create an account and join the service.

Until Tuesday, anyone hoping to join Bluesky needed an invitation, which typically meant hunting down an existing member and begging for an invite. That invite-only period gave the site time to build out moderation tools and other features, Bluesky said.

Bluesky resembles Twitter — now known as X after Tesla billionaire Elon Musk paid $44 billion for the company — in many respects, although it doesn’t yet offer direct messaging between users. It does offer more customization options, though whether these will appeal to users isn't yet clear.

By default, Bluesky displays posts by accounts you follow in a linear timeline, although it’s also possible to switch to algorithm-driven timelines created by other users. The service does its own moderation but also plans to let its users stack together alternative moderation schemes. That feature hasn’t been enabled yet.

And once things really get going, Bluesky plans to set users free by allowing them to move their collections of friends, followers and other data to competing social networks. As the company says in a whimsical cartoon page included in Tuesday's announcement, Bluesky aims to be “ the last social account you'll ever need to create.”

In practice, it probably won't be that easy. The technical term for making social networks interoperable this way is “federation," and it turns out there are multiple ways sites can federate. For instance, Mastodon and similar microblogging sites — including Meta's Threads service — use a federation algorithm called ActivityPub that should allow users to move between them.

In fact, Threads has already begun experimenting with sharing posts to Mastodon and other services using ActivityPub. “Making Threads interoperable will give people more choice over how they interact and it will help content reach more people,” Meta CEO Mark Zuckerberg wrote in a Threads post in December. “I’m pretty optimistic about this.”

By contrast, Bluesky adopted a federation algorithm called the Authenticated Transfer Protocol and is so far the only such service using it. A “frequently asked questions” page for the protocol argues that ActivityPub makes it cumbersome to transfer accounts and that it lacks other important features.