Developer guide

Documentation topics

Getting Started

A step-by-step beginner's guide to getting involved with Mozilla.

For new Mozilla developers

A directory of articles which are particularly helpful for new Mozilla developers.

Working with Mozilla Source Code

A code overview, how to get the code, and the coding style guide.

Build Instructions

How to build Firefox, Thunderbird, SeaMonkey, or other Mozilla applications.

Editor Configuration

Tips on setting up your favorite IDE or text editor to work with Mozilla projects.

Development process overview

An overview of the entire Mozilla development process.

Managing multiple profiles

When working with prerelease versions of Firefox, it's often helpful to have multiple Firefox profiles, such as one for each channel, or for different kinds of testing.

Automated Testing

How to run Mozilla's automated tests, and how to write new tests.

How to submit a patch

After getting your patch written, you need to get it checked into the tree. This article explains the review process and how to get your patch approved.

Getting documentation updated

How to ensure that documentation is kept up to date as you develop.

Mozilla modules and module ownership

This article provides information about Mozilla's modules, what the role of a module owner is, and how module owners are selected.

Code snippets

Useful code samples for a wide variety of things you might need to figure out how to do.

Mozilla development strategies

Tips for how to make the most of your time working on the Mozilla project.

Debugging

Find helpful tips and guides for debugging Mozilla code.

Performance

Performance guides and utilities to help you make your code perform well (and to play nicely with others).

The Mozilla platform

Information about the workings of the Mozilla platform.

Adding APIs to the navigator object

How to augment the window.navigator object with additional APIs.

Interface Compatibility

Guidelines for modifying scriptable and binary APIs in Mozilla.

Customizing Firefox

Information about creating customized versions of Firefox.

Task-Graph Generation

What controls the jobs that run on a push to version control?  How can you change that?

Virtual ARM Linux environment

How to set up an ARM emulator running Linux for testing ARM-specific, but not necessarily platform-specific, code. Useful for mobile developers.

Obsolete Build Caveats and Tips

A place to put build tips which are no longer relevant to building the latest version of the code from main but are relevant when building old codebases.

Tools

Bugzilla

The Bugzilla database used to track issues for Mozilla projects.

DXR

Next generation of searching Mozilla's source code. In active development.

SearchFox

Another option for Mozilla code searching. Indexes JS as well as C++, includes blame capabilities. In active development.

Mercurial

The distributed version-control system used to manage Mozilla's source code.

Mozilla build VM

A VirtualBox compatible virtual machine configured with all the software needed to build and work on Firefox.

TaskCluster

TaskCluster is the task execution framework that supports Mozilla's continuous integration and release processes.

Treeherder

Treeherder shows the status of the tree (whether or not it currently builds successfully).  Check this before checking in and out, to be sure you're working with a working tree.

Perfherder

Perfherder is used to aggregate the results of automated performance tests against the tree.

Crash tracking

Information about the Socorro crash reporting system.

Callgraph

A tool to help perform static analysis of the Mozilla code by generating callgraphs automatically.

Developer forums

A topic-specific list of discussion forums where you can talk about Mozilla development issues.

Mozilla Platform Development Cheat Sheet

Brian Bondy's list of frequently referenced information for platform developers.

Firefox development video tutorials

Brian Bondy's video tutorials on Firefox development.