This new engine is named Quantum and was announced past year as a savior for Firefox's sluggish Gecko engine that was built two decades ago, in 1997, for the now dead Netscape browser. As highlighted in the video below, the new browser often appears faster than Chrome.
Firefox Quantum spearheads Mozilla's effort to win back users lost to Chrome since Google released it in 2008, and revive its position as a formidable rival in the browser wars as it once was against Internet Explorer in the 2000s. Among the updates, says Mozilla, is the ability to use multiple cores - something Firefox hasn't done in the past. It is, in fact, taken from its Project Quantum endeavor to speed up Firefox and catch up with the market.
In introducing Quantum, Mozilla makes no secret of who the primary targets for the upgraded browser will be. That's only around 25% of all legacy plugins, meaning that almost 75% of all Firefox add-ons won't be available to users on the new version.
Firefox Quantum also prioritizes the tab you're now using, so it downloads and runs before those in the background, cutting RAM usage by around 30%.
Performance aside, Firefox Quantum includes a visual refresh, called Photon, that "looks and feels right at home with modern operating systems".
While performance improvements are clearly the main part of Firefox 57 beta and the stable version that will come after, there are still plenty of other new features.
The new browser boasts an interface redesign featuring square tabs, menus that change size based on whether you're clicking with a mouse or a finger, extensions (like Chrome's), and your browsing history, downloads, bookmarks, and screenshots consolidated in a "Library". No other browser can do this.
Firefox Quantum sports a simpler logo than earlier versions of Mozilla's browser. Quantum has also received a tweaked UI that is meant to work well with the high DPI display common on devices today. When you open a new tab, you'll see now trending web pages recommended by Pocket users so you won't miss out on what's hot online, as well as your top sites.
As always, developers will want to take a close look at what's in the pipeline.
Mozilla is planning to release Firefox 57 on November 17.
Firefox is also getting a visual makeover. The latest beta of Firefox from Mozilla has been released and it will be the first major release to finally drop support for Flash.