Addons-Server is the code that powers addons.mozilla.org (AMO), Mozilla's catalogue of Firefox extensions and themes. It is a Django application with an API that handles add-on listings, uploads, review workflows and the services other Mozilla products rely on.

Why it is interesting

• A large, production-proven example of a Python and Django marketplace for software add-ons
• Developer documentation for running the stack locally, plus development and staging environments
• An open community on Matrix for contributors

It is mainly useful to Mozilla contributors, extension authors who want to understand how listings are processed, and teams studying how to build a large extension store.