Mozilla Developers

Developer tools, resources, videos and more

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.

More about WebAssembly

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

  • Fluent 1.0: a localization system for natural-sounding translations

    Fluent is a family of localization specifications, implementations and good practices developed by Mozilla. With Fluent, translators can create expressive translations that sound great in their language. Today we’re announcing version 1.0 of the Fluent file format specification. We’re inviting translation tool authors to try it out and provide feedback.

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  • Pyodide: Bringing the scientific Python stack to the browser

    Pyodide is an experimental project from Mozilla to create a full Python data science stack that runs entirely in the browser. We think it’s worthwhile to work on moving the JavaScript data science ecosystem forward, and that’s why we built and released Iodide earlier this year. In the meantime, we’re meeting data scientists where they are by bringing the popular and mature Python scientific stack to the browser.

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  • Developer Roadshow 2019 returns with VR, IoT and all things web

    Mozilla Developer Roadshow is a meetup-style, Mozilla-focused event series for people who build the web. In 2017, the Roadshow reached more than 50 cities around the world sharing highlights of Mozilla and Firefox technologies. Now, we’re back! To open our 2019 series, Mozilla presents two events with VR visionary Nonny de la Peña and the Emblematic Group in Los Angeles and in New York.

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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