https://techcrunch.com/2021/09/16/liveblocks-is-an-api-that-lets-you-add-real-time-collaboration-to-your-product/

Meet Liveblocks, a startup that has been working on a set of APIs so that it’s easier to build a collaborative product. Essentially, it lets you create multiplayer experiences on the web or in your app.

The company started with a live presence state API. If you integrate this API in your product, it means that you can show when somebody joins a page, a project or a document by displaying an avatar in a corner. You can also share the position of everyone’s cursor, text selection or content selection in real time.