Mozilla Developers

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Firefox Quantum: Developer Edition

Get the latest features, fast performance, and the development tools you need to build for the open web.

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Developer resources

MDN

The best resource for the Open Web.

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Firefox DevTools

Edit and debug HTML, CSS, and JavaScript.

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WebAssembly

Use the .wasm format as a compiler target.

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Cross-browser testing

Easily test your site on every browser and operating system.

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Events to check out

Fresh from our blog

Fresh from our blog

  • Firefox 66: The Sound of Silence

    Firefox 66 is out, and brings with it a host of great new features like screen sharing, scroll anchoring, autoplay blocking for audible media, and initial support for the Touch Bar on macOS.

    Read more

  • A Homepage for the JavaScript Specification

    Ecma TC39 has shipped a website for following updates to the JavaScript specification. It’s the first part of a two-part project to help people find the information they need in order to understand the specification and our process. The current website is a simple MVP that provides links to our most significant documents, as well as a list of proposals that are near completion. We will experiment with other features as the need arises.

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  • Fast, Bump-Allocated Virtual DOMs with Rust and Wasm

    Dodrio is a new virtual DOM library that is designed to leverage the strengths of both Wasm’s linear memory and Rust’s low-level control by making extensive use of fast bump allocation. Early benchmarking results validate Dodrio’s design and show that it already has best-in-class performance. Now we’re seeking feedback from real-world usage.

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Projects we love

A new layout system for the Web.

See grids in action

Mozilla’s next-generation web engine.

Get involved

A systems programming language that is fast and safe.

Check out Rust

Powerful Web technologies that help push games to the new level.

Learn more

Build exciting virtual reality Web pages using HTML.

Start building