HTML5 IS BIG
When I think of HTML5, I’m reminded of a quote about space by one of my favourite authors –Douglas Adams. “Space,” says Adams, “is big. Really big. I mean, you may think it’s a long way down to the chemist’s but that’s just peanuts to space.” And the reason this quote reminds me of HTML5 is because HTML 5 is big. Really big. I mean you may think it’s a long way… Well, you get the idea.
HTML5 is a set of guidelines released by the World Wide Web Consortium (the “W3C” for short) with input from the most popular browser manufacturers, such as Microsoft, Google, the Mozilla Foundation, and Apple.
The browser manufacturers are implementing the HTML5 guidelines at their own pace and in their own order. Due to the enormous scope of HTML5 and the rate at which users tend to upgrade to new browsers, it is unlikely that HTML5 will be on all computers for another decade. Does this mean that HTML5 is irrelevant today? Of course not! Each browser manufacturer is working furiously to implement new features into their browser and encouraging users to upgrade to the latest browser.
You as a developer can start taking advantages of these features today. The challenge, of course, is to build a web application that will use features of new browsers, but still be useable if a user connects with an older browser that does not support the new features. This backwards compatibility is known as “graceful degradation”, meaning that your application downgrades itself gracefully rather than crashing when it encounters a degraded browser. We will talk about ways of making your pages and applications degrade gracefully throughout this paper.
The W3C had several goals when defining HTML5, including Simplicity, Semantic Markup, and ???
HTML5 is simpler than earlier versions of HTML. For example, the mysterious document declaration at the top of each HTML document has been simplified from
DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
This new version is simple enough that we actually have a prayer of memorizing it.