Mozilla released a big overhaul of Firefox they call "Quantum" awhile ago, but they left out one key piece of technology that wasn't ready yet. "Webrender," as Mozilla calls it, works more like a game engine than a traditional browser renderer, painting every pixel on every frame to make browsing as smooth as possible. In a newsletter, a Mozilla developer says "WebRender should be generally usable on all platforms other than Android," and is automatically enabled on Firefox nightly builds if you have a desktop Nvidia GPU and Windows 10. On other hardware, you can manually turn webrender on in Firefox's settings. Even if most of your frames are best-case scenarios - that is, they only take up a tiny bit of the frame budget - you can still get choppy motion. For perceptible jank, only a couple of frames need to fall into worst-case scenarios. These scenarios are called performance cliffs. Your app seems to be moving along fine until it hits one of these worst-case scenarios (like animating background color) and all of the sudden your app's frame rate topples over the edge. But we can get rid of these performance cliffs. How do we do this? We follow the lead of 3D game engines.