Lastly, the “Quantum DOM” project began overhauling how Firefox prioritizes work, responding more quickly to events like user input while delaying less urgent computations until the browser is idle. Compared to Firefox six months ago, today’s Developer Edition is twice as fast on benchmarks like Speedometer 2.0 that simulate the real-world performance of modern web applications.
Firefox Quantum is now available in Developer Edition, and this Firefox is fast.
So, if you point your browser at https://addons.mozilla.org/en-US/firefox/tag/firefox57 you will get 2273 add-ons right now To put this into perspective: Mozilla AMO lists 18814 add-ons right now.
Not all of those are compatible with the current version of Firefox, Firefox 53 at the time of writing.
Lastly, Firefox’s preferences were completely redesigned and are now searchable.
Firefox Quantum: Developer Edition also includes a ton of refined, redesigned, and brand new developer tools.
A part of those add-ons will be turned into Web Extensions by their developers, or by users who forked a particular extension so that it remains available for a Web Extensions exclusive Firefox browser.