Codebases

Like many large software projects, Tor Browser is the integration of many distinct codebases.

Tor Browser: Every branch is a Firefox version plus Tor Browser patches
Torbutton: Previously a Firefox addon, now a built-in extension providing a variety of protections and functionality
Tor Launcher: Previously a Firefox addon, now a built-in extension providing the configuration UI and controlling the underlying tor process
Fenix: Every branch is a Firefox for Android version plus Tor Browser patches
Android Components: Every branch is a Mozilla Android Components (MozAC) branch plus Tor Browser patches
Tor Android Services: Android Tor controller
Tor Browser Build: The reproducible build system