ActivityPub
ActivityPub is an open, decentralized social networking protocol that enables servers to communicate and share social activities, such as posts, likes, and follows, across different platforms. It is a W3C standard that defines a client-to-server API for creating, updating, and deleting content, as well as a server-to-server API for federated interactions between independent servers. This allows users on different social media platforms to interact seamlessly, fostering interoperability in the fediverse.
Developers should learn ActivityPub when building or integrating social networking features that require decentralized, federated communication, such as in Mastodon, PeerTube, or other fediverse applications. It is essential for creating platforms that prioritize user control, data portability, and censorship resistance, as it enables cross-platform interactions without relying on a central authority. Use cases include implementing social feeds, notifications, and content sharing in distributed systems.