HTML5 is supposed to be what HTML should have been in the first place.
The first web browser, Mosaic, was introduced in 1993. A year later Netscape, based on Mosaic, was introduced and the net began to become popular. HTML was used in both browsers, but there was no "standard" HTML until the introduction of HTML 2.0.
HTML 2.0 was first published in 1995.* HTML 3.0 was published two years later and 4.01 two years after that. HTML 4.01 has been the work horse of the net ever since.
The first "working draft" of HTML5 came out in January of 2008 and it already has surprisingly broad browser support. However HTML5 is not yet fully implemented and won't be for some years yet. There are any number of planning committees that have plans to make it a "Recommendation", but such plans are still in the planning phase – and don't plan on that changing anytime soon. **
Two groups, the W3C and the WHATWG, are in charge of developing HTML5. Why two groups? "The WHATWG was formed in response to the slow development of web standards monitored by the W3C." wikipedia – In other words they got in a fight and parted ways.
They say they have since kissed and made up. Both groups agree that it's going to take years to fully implement HTML5, though it will be in wide use long before then – assuming that, like eColi, they don't divide and multiply again.
Many on the boards of W3C and WHATWG work for competing browser companies. Inevitably conflicts of interest (for example MS's brutal attempt in the late 1990s to control it all - wikipedia), have provoked problems, but I will admit – albeit begrudgingly, that on the whole they have done a reasonably good job.
In many ways HTML5 is not all that different that 4.01. Certain tags, such as the
<font> tag, that were "deprecated" (but worked) in HTML 4.01, don't work in HTML5. There are a number of other odds and ends that have been changed, but they tidy up old messes rather than introduce fundamental changes.
Fundamental changes are coming with the development of APIs that will run in HTML5 – exciting and powerful new tools that will take the internet places we can't begin to imagine. Also new elements such as the
<article> have been introduced which will help search engines analyze web pages better.
The internet will absorb television the way it has telephone technology. Now if you want to add video to your page you either have to add a complicated script to your page, embed a YouTube video or have to open it in a separate application such as Windows Media Player. The former is not easy and the latter two lack professional polish. HTML5's new
<video> tag will solve that problem. At the moment no one can agree on what video format to use. Eventually they will work that out and when they do making and distributing television programs will be within the reach of everyone who can make videos and write HTML.
If you want to see an example of what will be first sign up for YouTube's HTML5 beta http://www.youtube.com/html5, select "Join the HTML5 Trial". Then close that window, click http://www.youtube.com/embed/3NjXs_nXB5U and listen to Howlin Wolf ask "How Many More Years?" In theory there should be no problem but it is still in beta so who knows. ***
With the introduction of IE9 even Microsoft is getting on board with most of HTML's newer elements. Chrome, Firefox, Opera and Safari have complied to most HTML5 standards for some time.
HTML5 is not just the future of web design, it's the present.
Application Programming Interface - API are how HTML5 will realize its full potential.
* "There was no HTML 1.0; the 2.0 designation was intended to distinguish the new edition from previous drafts." wikipedia.
** In February 2011 they extended the target date for Recommendation to 2014, however it wouldn't surprise me in the least if they extend it then too. w3.org
*** Please contact me if this doesn't work.