Recent Articles

  • Andrew Halberstadt

    Testing Firefox more efficiently with machine learning

    A browser is an enormously complex piece of software, and it's always in development. About a year ago, we asked ourselves: how could we do better? Our CI relied heavily on human intervention. What if we could instead correlate patches to tests using historical regression data? Could we use a machine learning algorithm to figure out the optimal set of tests to run? We hypothesized that we could run fewer tests to save money, get results faster, and reduce the cognitive burden on developers.

  • Adding prefers-contrast to Firefox

    When we talk about the contrast of a page, or contrast between web elements, we’re assessing how color choices impact readability. For visitors with low vision, web pages with low or insufficient contrast can be hard to use. In this article, we’ll walk through the design and implementation of the prefers-contrast media query in Firefox, and look at why it's so exciting and important.

  • Securing Gamepad API

    As part of Mozilla’s ongoing commitment to improve the privacy and security of the web platform, over the next few months, we will be making some changes to the Gamepad API. Starting with Firefox 81, the Gamepad API will be restricted to what are known as “secure contexts.”

  • New in Firefox 78: DevTools improvements, new regex engine, and abundant web platform updates

    Firefox 78 heads heads out the door with a new regex engine, updates to the ECMAScript Intl API, new CSS selectors, enhanced support for WebAssembly, some important WebExtensions API updates, and many improvements to the Firefox Developer Tools.

  • Mozilla WebThings Gateway Kit by OKdo

    Mozilla WebThings Gateway is an open source software distribution focused on privacy, security, and interoperability. It provides a web-based user interface to monitor and control smart home devices over the web. OKdo, a UK vendor offerings IoT technology for hobbyists, educators, and entrepreneurs, has announced the release of the WebThings Gateway Kit, with everything you need to get the Gateway up and running in minutes.

  • Welcoming Safari to the WebExtensions Community

    Browser extensions give people a way to take control of how they experience the web. This week Apple has announced that Safari is adopting a web-based API for browser extensions similar to Firefox’s WebExtensions API, making it easy to build once and run in multiple browsers. Developers can get started with Firefox Extension Workshop or consult the comprehensive documentation on MDN for API coverage details.

  • Compiler Compiler: A Twitch series about working on a JavaScript engine

    Yulia Startsev, a JavaScript engineer on Firefox's SpiderMonkey team, introduces her new Twitch stream called Compiler Compiler. In the three opening interactive episodes, we get an inside look at how the JavaScript Specification, ECMA-262, is implemented in SpiderMonkey, by reading the spec and fixing issues in the implementation.

  • Introducing the MDN Web Docs Front-end developer learning pathway

    The MDN Web Docs Learning Area teaches fundamentals of modern web development, beginning with HTML, CSS, and JavaScript essentials. In feedback this year, readers asked for a more opinionated, structured approach. They asked for coverage of client-side tooling, frameworks, transformation tools, and deployment tools widely used in today's workplace. Meet the Front-end developer learning pathway from MDN.

  • A New RegExp Engine in SpiderMonkey

    Regular expressions – commonly known as RegExps – are a powerful and heavily used tool for manipulating strings in JavaScript. This post describes how we updated the RegExp engine in SpiderMonkey, Firefox's JavaScript engine, by building a shim layer to V8's Irregexp. The outcome: reduced maintenance and stronger collaboration among the browsers, full support for all the new RegExp features, and compatibility with the latest ECMAScript standard.

  • New in Firefox 77: DevTool improvements and web platform updates

    Firefox 77 is now available with a variety of developer tool updates and new web platform features. With your feedback, we've removed performance bottlenecks, resulting in faster, leaner JavaScript debugging. We also report on some changes to Firefox extensions, including fewer permission requests.

  • Building FunctionTrace, a graphical Python profiler

    Firefox Profiler is a powerful web-based performance analysis interface featuring call trees, stack charts, flame graphs, and more. All data filtering, zooming, slicing, and transformation actions are preserved in shareable URLs. FunctionTrace is a low-overhead profiler that runs on unmodified Python applications. Integrated with Firefox, it's a new breed of analysis tool project built conveniently on top of the Firefox Profiler.

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