Firefox 57.0 Released
Hopefully most of the missing extensions will be developed sooner rather than later. I have 15 extensions installed, 14 of which are "Legacy".<p>The most critical one, Tree Style Tabs, has been converted. That was the key blocker that prevented me from seriously using Chrome. But many more remain; Cookie Controller, RefControl, some kind of Classic Theme Restorer equivalent (to get a menu bar back for Bookmarks, at a minimum), etc.