Under the hood: Facebook Messenger for Firefox

This post details the integration of Facebook Messenger into Firefox 17, leveraging HTML5 WebSockets and Shared Workers. It highlights the use of WebSockets for efficient, persistent client-server connections and the MQTT protocol for bandwidth optimization. Shared Workers are used to synchronize state across various Facebook elements (notifications, chat tabs, etc.) without redundant data fetching. The post also discusses the challenge of reusing existing JavaScript libraries within a DOM-less Shared Worker context and the solution of adapting these libraries to remove DOM dependencies.