Back then, Gecko was already complex. Firefox streamlined the UI, dropping for instance the Email client and unnecessary widgets. It can be done. Just the engi

Back then, Gecko was already complex. Firefox streamlined the UI, dropping for instance the Email client and unnecessary widgets. It can be done. Just the engine remains complex, but it‘s not that big a problem. If needed, we can add a new doctype, just like HTML5 that puts the browser into some sort of strict mode where features are dropped.