If you’re (like me) still working on projects that must work in browsers without great support for HTML5, you might be interested in this article I recently wrote for MSDN’s Script Junkie. It doesn’t go deep into particular implementations, but focuses more on what a polyfill is, why a polyfill is more useful than an arbitrary JavaScript utility library, and then does into a few concrete examples.

Taking advantage of HTML5 in real-world sites and applications can be a daunting proposition. Though modern browsers are implementing HTML5′s new features at a rapid pace, few of us are lucky enough to write applications supporting only the latest crop of browsers. As a professional web developer, that browser fragmentation forces you to spend significant effort navigating the uncomfortable space between the promise of the future and the realities of the present. The good news is that Internet Explorer 10 and 9 support HTML5. Users are also leaving older versions of Internet Explorer. But the share of older versions is likely to remain just enough for developers to support in the foreseeable future.

However, that doesn’t mean you have to give up on supporting HTML5 in the near term. Just as there are techniques for a site to gracefully support variances like multiple screen sizes and different levels of CSS capability, it’s also possible to achieve surprisingly robust cross-browser HTML5 support. Even though older browsers lack many of HTML5’s new APIs, JavaScript is an incredibly flexible language and exposes opportunities to retroactively add new features when they aren’t natively present.

Continue reading HTML5 Now: Getting More Through Polyfills on MSDN »