The document discusses the Firefox OS, an open source mobile operating system developed by Mozilla. It is based on web technologies like HTML5, CSS3, and JavaScript. The OS uses the Gecko rendering engine and is divided into three main components - Gaia for the user interface, Gecko for running web apps, and Gonk which provides the Linux kernel and hardware abstraction layer. The document outlines the architecture, working, advantages and opportunities that Firefox OS provides for developers to build apps using web standards.