Article: Offline JavaScript PubSub between browser tabs by Simon Frey

Simon made his own PubSub system using the browser’s local storage, allowing offline communication between browser tabs (no server needed!). I love how he shows examples of this system in action, it’s really cool to see how song progress is saved across multiple tabs.

TabSub in action
Inspection of Local Storage using TabSub in his article

Like Simon said, the Broadcast Channel API does the same thing but is available in all browsers. Another tool to add to the toolbox!