# Contributing to Mozilla projects

This page is here to help you get from "I want to build Firefox"
to "I'm building my own Firefox" to "I can contribute to Firefox".
So if you'd like to help Mozilla build the best web browsers in the
world, you're in the right place.

```{rubric} Need help?
:name: Need_help
```

The Mozilla community prides itself on being an open, accessible, and
friendly community for new participants. If you have any difficulties
getting involved or finding answers to your questions, please [come and
ask your questions in our
chatroom](https://chat.mozilla.org/#/room/#introduction:mozilla.org),
where we can help you get started.

We know even before you start contributing that getting set up to work
on Firefox and finding a bug that's a good fit for your skills can be a
challenge, and we're always looking for ways to improve this process: making
Mozilla more open, accessible, and easier to participate with. If you're
having any trouble following this documentation, or hit a barrier you
can't get around, please join us in the Introduction room on Matrix.

## What skills do I need?

Mozilla maintains small and large projects and we are thrilled to have contributors with
very diverse skills:

- If you know **C++,** **Rust,** **JavaScript,** **HTML** or **CSS**,
  you can {ref}`contribute to the core layers <Firefox Contributors' Quick Reference>` of
  Firefox and many other Mozilla projects.
- If you know **Rust**, you can also contribute to the [Rust programming
  language](https://github.com/rust-lang/rust) itself, numerous crates like [grcov](https://github.com/mozilla/grcov/)
  or [Stylo](/layout/StyleSystemOverview.html), Firefox's parallel CSS engine, {searchfox}`WebRender <gfx/wr/>`, Firefox's GPU-based 2D rendering engine, and [Neqo](https://github.com/mozilla/neqo), our QUIC/HTTP3 networking stack.
- If you know **Kotlin**, you can contribute to {ref}`Firefox for Android <Firefox Contributors' Quick Reference>` (code name: "Fenix"). {searchfox}`Fenix's code <mobile/android/>` is integrated into the same repository as Firefox Desktop.
- If you know **Swift**, you can contribute to [Firefox and Firefox Focus for
  iOS](https://github.com/mozilla-mobile/firefox-ios).
- If you know **C++**, you can contribute to our [VPN client](https://github.com/mozilla-mobile/mozilla-vpn-client).
- If you know **C++** and programming language implementations, you can contribute to [SpiderMonkey](https://spidermonkey.dev/), our JavaScript engine.
- If you know **JavaScript**, you can contribute to [PDF.js](https://github.com/mozilla/pdf.js), the PDF viewer shipped with Firefox.
- If you know **C++**, **JavaScript** or **machine learning**, you can contribute to [Firefox Translations](https://github.com/mozilla/translations), our local, privacy-preserving translation engine.
- If you know **Make**, **shell**, **Perl**, or **Python**, you can
  contribute to our build systems, release engineering, and automation.
  If you know **Rust**, you can also contribute to [sccache](https://github.com/mozilla/sccache/),
  our compiler caching tool used to speed up Firefox builds.
- If you know **Go** or **JavaScript**, you can contribute to [Taskcluster](https://github.com/taskcluster/taskcluster), our CI infrastructure.
- If you know **C**, you can contribute to [NSS](/security/nss/index.html), our cryptography library.
- There are even many ways to contribute to the Mozilla mission without
  programming. If getting involved in design, support, translation,
  testing, or other types of contributions sparks your interest please
  see the [Volunteer Opportunities
  wiki](https://contribute.mozilla.org) or the [Mozilla
  community](https://community.mozilla.org/) site.

Perhaps you do not know programming yet, but you want to start learning?
There are [plenty of
resources](https://developer.mozilla.org/learn) available on
the MDN Web Docs!