Firefox OS is a new mobile operating system developed by Mozilla's Boot to Gecko (B2G) project. It uses a Linux kernel and boots into a Gecko-based runtime engine, which lets users run applications developed entirely using HTML, JavaScript, and other open web application APIs.
Firefox OS is currently under heavy development; we are constantly working on ways to make it easier for you to use and hack on Gaia and create apps. However, you need knowledge about systems in order to do things like build the entire Firefox OS stack, or flash a phone with a build of Firefox OS. Linked below are guides meant for Web developers interested in running and making changes to Gaia or developing apps to run on Firefox OS devices.
Documentation about the Firefox OS platform, including Gonk, Gaia, and everything in between. This includes documentation for building and installing the platform onto devices, as well as building the simulator and emulators.
Documentation about security in Firefox OS; this includes topics about security devices from every perspective: for app developers, device integrators, and so forth.
A guide to the Firefox OS developer phones Mozilla provides to some developers. This guide also applies if someone installed Firefox OS on your phone for you.