TML 5 is an interesting beastie. The specification was not planned; The W3C was committed to HTML 4.1 as the last word in HTML. As such, most of the requests for HTML 5 came from the HTML user community itself, largely through the advent of the Web Hypertext Application Technology Working Group (WHATWG). The push from WHATWG was strong enough to prompt the formation of a HTML 5 working group a couple of years ago. Since then, the HTML 5 working group has slowly gone through the process of taking a somewhat hand-waving specification and recasting it in W3C terms, along with all the politics that the process entails.
On April 23, 2009, the HTML 5 group released the most recent draft of the specification. Overall, it represents a considerable simplification from the previous release, especially as a number of initially proposed changes to the specification have been scaled back. The group defined roles for the proposed changes elsewhere.
HTML 5 is a broad specification, and consequently, dozens of distinct changes—more than a single article can reasonably cover in any detail—occurred between HTML 4 and 5. This article focuses on the HTML 5 layout elements. Subsequent articles will examine forms-related changes (which are substantial), the new media elements, and DOM-related changes.