An anonymous reader quotes a report from TechCrunch: Tumblr will add support for ActivityPub, the open, decentralized social networking protocol that's today powering social networking software like Twitter alternative Mastodon, the Instagram-like Pixelfed, video streaming service PeerTube, and others. The news was revealed in a response to a Twitter user's complaint about Mastodon's complexities. Automattic CEO Matt Mullenweg -- whose company acquired Tumblr from Verizon in 2019 -- suggested the user "come to Tumblr" as the site would soon "add activitypub for interconnect." "Don't stress," he said, before clarifying that Tumblr first has to deal with the waves of new users coming in right now from Twitter, but that support for "interop and activitypub" were due to come "ASAP." In short, this announcement means Tumblr would move from being only a niche blogging platform to instead become a part of a larger, decentralized social network of sorts -- and one whose user base has grown in size in recent days as people flee Elon Musk's Twitter in search of new communities.

The ActivityPub protocol, its website explains, provides a client-to-server API for creating, updating, and deleting content as well as a federal server-to-server API for delivering notifications and subscribing to content. In practice, this means that Mastodon users can interact and follow users on other instances (independently run nodes), as well as with users on other social apps (like PeerTube), which also support the implementation of ActivityPub. It makes for a web of social networks where users can find and follow each other without having to set up new accounts on each new service. This is the opposite approach to today's "walled garden" social networks, where a post on one platform can't be viewed by those on others, unless you re-upload or repost the content directly or share a link to the other site where the content can be found.