We’ve released a very early draft of the Block Protocol, and we’ve started building some very simple blocks and a simple editor that can host them. If you work on any kind of editor—be it a blogging tool, a note-taking app, a content management system, or anything like that—you should allow your users to embed blocks that conform to the Block Protocol. If you work on any kind of custom data type that might make sense to embed in web pages, you should support the Block Protocol.