Mozilla is working on a major overhaul of its Firefox browser, and, with the general release of Firefox 57 today, has reached a major milestone. The version of the browser coming out today has a sleek new interface and, under the hood, major performance enhancements, with Mozilla claiming that it's as much as twice as fast as it was a year ago. Not only should it be faster to load and render pages, but its user interface should remain quick and responsive even under heavy load with hundreds of tabs.

Collectively, the performance work being done to modernize Firefox is called Project Quantum . We took a closer look at Quantum back when Firefox 57 hit the developer channel in September , but the short version is, Mozilla is rebuilding core parts of the browser, such as how it handles CSS stylesheets, how it draws pages on-screen, and how it uses the GPU.

This work is being motivated by a few things. First, the Web has changed since many parts of Firefox were initially designed and developed; pages are more dynamic in structure and applications are richer and more graphically intensive. JavaScript is also more complex and difficult to debug. Second, computers now have many cores and simultaneous threads, giving them much greater scope to work in parallel. And security remains a pressing concern, prompting the use of new techniques to protect against exploitation. Some of the rebuilt portions are even using Mozilla's new Rust programming language, which is designed to offer improved security compared to C++.

While today's release represents a major step forward in the browser's performance and reliability, work on Quantum continues. One major weakness of Firefox, relative to Chrome and Edge, is its use of sandboxing and process isolation to limit the impact that security flaws can have. Next year Mozilla will be working to improve these areas. Early next year should also see the rollout of a new GPU-accelerated rendering engine.