Mozilla projects on GitHub

There are a number of tools and services whose code is hosted on GitHub. This article offers a quick guide for getting started with Mozilla code on GitHub. It also lists some interesting GitHub repositories containing Mozilla project code.

Getting started

You can look at code on GitHub without an account. That is the first thing to know. To do more—to contribute to the code, or to fork it and start your own project based on Mozilla-related code—you need a GitHub account. To learn more about setting up a GitHub account, visit the GitHub website.

Most Mozilla project code is located in repositories within the Mozilla GitHub organization. This is a great place to start looking for any projects not listed below.


This listing covers the larger-scale and more important Mozilla projects on GitHub. It does not include everything since it's hard to keep track of all the smaller projects. Look to GitHub for the most complete list of Mozilla projects on GitHub.

Project name Description
PDF.js A Portable Document Format (PDF) reader written entirely in JavaScript.
Shumway Shumway is a Flash VM and runtime written in JavaScript.
addon-sdk The Mozilla Add-on SDK.
asknot The What Can I Do For Mozilla web site, which helps you figure out how you can contribute to Mozilla.
bugsahoy A Web page to help new Mozilla contributors identify bugs to fix.
bugzilla-dashboard A convenient dashboard to help you get an overview of your bugs.
codefirefox The CodeFirefox site, with videos and tutorials about how to contribute to the Firefox project and Mozilla code in general.
debugger.html The debugger.html, a modern universal JS debugger for Firefox DevTools, Node, and every other JS environment.
dxr An intelligent tool for browsing source code.
emscripten The Emscripten LLVM-to-JavaScript compiler.
fxdt-adapters The Firefox Developer Tools Adapter that lets you debug various remote targets from the Firefox Developer Tools. A Web page to help new Mozilla contributors find bugs to work on that relate to the Firefox Developer Tools.
gecko-dev A read-only mirror of the Mercurial repositories used for Mozilla private code.
kitsune Kitsune is the platform that drives the Mozilla support web site, SUMO.
kuma The Django project that powers this site (MDN).
mdn Code samples for the MDN Web site.
mozbrick The Mozilla Brick project.
mozilla-B2G The Firefox OS project.
mozilla-appmaker The Appmaker project -- a Web tool to let non-programmers create apps.
mozilla-l10n Scripts and tools used by the localization drivers.
mozilla-metrics Tools used to collect metrics about Mozilla code.
mozilla-services Mozilla cloud services projects.
opennews The Knight-Mozilla Open News project, helping the journalism/technology community do great work through shared knowledge and code.
PluotSorbet A J2ME-compatible virtual machine written in JavaScript.
rust-lang The Rust programming language, designed for safe concurrent code.
servo The next-generation rendering engine.