The World Wide Web consortium (W3C) has published a draft spec of the first major upgrade to HTML since 1997. HTML 5 features APIs for drawing two-dimensional graphics and control of audio and video content. The final version of the specification is not expected until late-2010.

HTML 5 is intended to boost interoperability and reduce software costs by providing rules on handling correct HTML documents and recovering from errors.

Catching up to how HTML actually is practised versus what the specifications say should be practiced and adding new features, said Dan Connolly, a co-chair of the W3C HTML Working Group. "We've been doing a lot of things [since the last upgrade], but basically, the scale of the web went way up, and the scale of our efforts really didn't match it until now," he said.

New features mostly pertain to web applications and integrating video as a first-class medium on the web, Connolly said. In proposing its new features, W3C studied what people do on the web and what leading-edge websites do. "Now it's time to standardise them," so these capabilities can show up in authoring tools, said Connolly.

By standardising these capabilities, they become easier to learn, and it is easier to hire someone who can tackle these tasks, according to Connolly.

Other new capabilities planned for HTML 5 include the ability for users to edit documents and parts of documents interactively. Also planned are features to make it easier to represent familiar page elements, including section tags, page footers, and navigation elements. Maintenance of persistent client-side storage is another highlight in version 5.

In developing a new standard, W3C was mindful of web progressions, such as the emergence of media-rich websites over static page collections, and innovations like AJAX. Recent innovations have boosted demand for a standard for building Web applications that interoperate across mobile and desktop platforms, W3C said.

W3C will need adoption of HTML 5 by companies supplying browsers, said Jeffrey Hammond, Forrester senior analyst. "I guess the big comment that I would have is [HTML 5 is] going to be important to the extent that browsers move forward and adopt it," he said. "Developers are interested in writing HTML that goes to as many browsers on as many devices as possible."

Mozilla already is supporting HTML 5 in its Firefox browser, the company said.

"Mozilla has been actively involved in the WHATWG (Web Hypertext Application Technology Working Group) applications spec, which is the basis for HTML 5," said, Vlad Vukicevic, infrastructuralist for Mozilla. "Firefox 3 supports many parts of the proposed standard, including DOM (Document Object Model) Storage, offline apps, the HTML Canvas, and many smaller features. While we are supporting these parts, there are other parts of the full HTML 5 proposal that are still under discussion."

Other browser companies, including Microsoft, Apple and Opera, are active participants in the HTML Working Group, W3C said.

Capabilities offered in HTML 5 currently are being offered through plug-in technologies, such as Adobe Flash and Microsoft Silverlight, Hammond said.

"The most interesting thing will be what happens when those capabilities get into native HTML and what impact that has on the rich Internet development market," he said. Specific plug-in technologies are not supported on every platform, he said. "[Thus], as a developer I might be more interested in writing HTML 5," Hammond said.

The finalisation of the specification will take some time, though. The plan is to have it available in a preliminary candidate recommendation form in the middle of 2009 and as a formal, final recommendation by September 2010, Connolly said. The process is lengthy because it takes time to get the technology to the point where Web authors can rely on it, he said. "It's up to each web author to decide when he wants to implement new features," he noted.

Also new to HTML 5 is it will be the first version implemented under the W3C Royalty-Free Patent Policy. This gives implementers greater assurance that standards can be implemented free of royalties, W3C said.