Building Polyfills

Chapter 6. The Future of Polyfilling

As our browsers release updates at a faster and faster clip, and legacy browsers like IE6–8 decline in global use, it’s easy to fall into the trap of thinking that polyfilling, as an idea, is becoming increasingly irrelevant. And while it’s true that “classical” polyfills for popular HTML5 and CSS3 features are being used less and less, for every mainstream feature in the web platform, like CSS3 animations, we’re seeing three or four new ideas and technologies introduced via the W3C or WHATWG and landing in one or more browsers. HTML5 and friends may have modernized the Web and our browsers in key ways, but don’t think for a moment that they also brought feature parity along for the ride.

Polyfilling: Not Just For Older Browsers

The bottom line is this: each new feature that’s supported in Firefox but has yet to be implemented in Chrome, IE, or Safari needs a polyfill just as much as that local storage feature you’d like to offer to IE7 users. If newer technologies are to take off and become accepted by developers, we need to use them on actual sites. In some cases, we might take a forked experience approach and support the feature only where native to the browser. In many cases, however, new features bring capabilities that we wish to share with as many of our users as possible. In this case, pollyfilling is a must.

Prollyfilling: Extending the Web Forward

Sometimes, pollyfilling specified features isn’t always enough for us, ...