Firefox Articles
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Warp: Improved JS performance in Firefox 83
With Warp (also called WarpBuilder) we’re making big changes to our JIT (just-in-time) compilers, resulting in improved responsiveness, faster page loads and better memory usage. The new architecture is also more maintainable and unlocks additional SpiderMonkey improvements. This post explains how Warp works and how it made SpiderMonkey faster.
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Coming through with Firefox 82
As October ushers in the tail-end of the year, we are pushing Firefox 82 out the door. This time around we finally enable support for the Media Session API, provide some new CSS pseudo-selector behaviours, close some security loopholes involving the Window.name property, and provide inspection for server-sent events in our developer tools.
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A New Backend for Cranelift, Part 1: Instruction Selection
This post will describe my recent work on Cranelift as part of my day job at Mozilla. In this post, I will set some context and describe the instruction selection problem. In particular, I’ll talk about a revamp to the instruction selector and backend framework in general that we’ve been working on.
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To Eleventy and Beyond
Porting an established static website from one generator to another can be daunting. In this post, Add-ons Engineering Manager Stuart Colville recounts the experience of migrating Firefox Extension Workshop, Mozilla’s site for Firefox-specific extension development resources, from the Ruby-based site generator Jekyll to JavaScript-based Eleventy.
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Changes to SameSite Cookie Behavior – A Call to Action for Web Developers
Browsers are changing the default value of the
SameSite
attribute for cookies fromNone
toLax
. This will greatly improve security for users. However, some web sites may depend (even unknowingly) on the old default, potentially resulting in site breakage. At Mozilla, we are slowly introducing this change. And we urge web developers to test their sites with the new default. -
Firefox 79: The safe return of shared memory, new tooling, and platform updates
Firefox 79 offers a new Promise method, more secure
target=_blank
links, logical assignment operators, tooling improvements for better JavaScript debugging, and many other updates of interest to web developers. In addition, shared memory is back at last, with a safer implementation. -
Safely reviving shared memory
At Mozilla, we want the web to be capable of running high-performance applications so that users and content authors can choose the safety, agency, and openness of the web platform. Shared-memory multi-threading is an essential low-level building block for high-performance applications. However, keeping users safe is paramount, which is why shared memory and high-resolution timers were effectively disabled at the start of 2018, in light of Spectre. Until now...
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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.
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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. -
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.