Tumblr, Mastodon, and Interoperability

Matt Mullenweg, cofounder of WordPress and CEO of Automattic and Tumblr, announced that they'll implement ActivityPub in Tumblr. ActivityPub is the protocol Mastodon's servers use to interconnect to the federated network, and allows users from different Mastodon servers to interact with each other.

Come to @tumblr. We'll add activitypub for interconnect. Don't stress.

— Matt Mullenweg (@photomatt) November 21, 2022

That means that users on Tumblr will be able to follow and interact with users on the Mastodon network, and viceversa. This has many implications. I can't wait to see how this will evolve. What would Twitter look like if it embraced interoperability and supported ActivityPub?