A new social media platform called Bluesky just launched. It has the look and feel of Twitter, but there’s something unique about it. It uses the AT Protocol. This is different from Mastodon, which is an open source Ruby on Rails app that provides some “instance to instance federation features”.
How Mastodon federation works, and why AT is different Anyone who wants to make a Mastodon instance just needs to check out a copy of the code and then deploy it with their own URL.