The promise of a richer browsing experience, based on a range of new features, including direct support for displaying video content, is being offered by the latest version of HyperText Markup Language (HTML), used by browsers to render web pages.

HTML has evolved over the years, with each new version enhancing the ways in which content can be displayed on web pages. Version 5, the latest, is still far away from being released as a final recommendation by the World Wide Web Consortium, the global web-standards setting body. Even so, it is being embraced in parts by all major browser makers, including Internet Explorer and Mozilla Firefox.

Ian Hickson, the editor of the specification, told The Hindu that the final completion date did not count for much given that it might be more than a decade away. “To publish a specification as a recommendation requires two complete and bug-free implementations and a test suite to prove this. By the time we've written such a large test suite and by the time browsers have advanced enough that they have no bugs in their implementation of HTML5, HTML5 will likely have long been forgotten and everyone will be talking about the next specification, or even the one after that!”

“Browser makers are not waiting for the HTML 5 specification to be finalised before implementing it. They are just waiting for parts of it to be stable (i.e. those parts which don't seem likely to be changed in the future),” said Shwetank Dixit, web evangelist, Opera Software. “Since some parts of the spec itself are in a flux, it really can't be said when the spec will fully be supported by any browser vendor,” he explained.

“What we're increasingly seeing is that through HTML5, web applications can provide users with richer interactive experiences, all working seamlessly, directly in web browsers,” says Arun Ranganathan, who works on the browser, Firefox, for the Mozilla Corporation.

One new HTML 5 feature that has got the technology world interested is its direct support for video and audio content. Till recently, browsers did not directly support the rendering of video; users had to download additional software, called plugins, to view video on web pages. But only select video codecs or formats are likely to be supported by the browsers, owing to certain considerations, especially those relating to digital rights management.

The use of plugins has been associated with a large number of security issues, “since they create an attack surface that isn't directly within the browser's control.” And by eliminating the dependence on plugins, “there are substantial performance and stability benefits,” says Mr. Ranganathan. It also paves the way for the creation of a new breed of applications that do things that third-party plugins cannot.

Local storing of data

One other big change is the potential HTML 5 holds for storing web data locally — on the user's computer — so that many tasks that are done online through web-based applications can be done offline too. Earlier, it was not possible to build this capability into web-based services, like Google's Gmail, without the use of additional software.

HTML 5-supported browsers will also be able to support the dynamic rendering of graphics using text-based scripts.

Another feature is in-built support for geo-location, or the capability to spot the user's geographical location with varying degrees of accuracy, depending on the technology deployed at the user's end. In Firefox, for instance, the feature has to be enabled by users for it to work, owing to privacy concerns. It becomes useful when customised information has to be delivered to users based on their location — like a list of restaurants in the area where they are located.

HTML 5 also makes it easier to build pages with drag-and-drop page elements, better menus and content that users can easily edit. It will also offer more options for structuring online forms. But experts say it may take time for the important specifications to be incorporated into the new versions of browsers.

“HTML5 and affiliated web technologies exposed to JavaScript (a scripting language widely used, along with HTML, in building web pages) are all about providing web applications with rich capabilities to delight users. This includes the ability for web applications to be used on multi-touch devices such as Netbooks, mobile phones, and tablet computers (all of which provide touch screens), or orientation events for devices with accelerometers,” says Mr. Ranganathan.

Keywords: HTMLFirefoxweb browser