Streamlining web language with HTML5

With the advent of Web 2.0, concerted efforts are being made to streamline the language used to develop web pages - enter HTML5, the first markup language update in a decade. Technology correspondent Jon Wilcox explains the implications.

Web 2.0 is still being fuelled by social networking sites such as Twitter, Facebook, Flickr, and YouTube, and the explosion of countless blogs around the globe. But it’s far from the end game. Despite the insistence of world wide web creator Sir Tim Berners-Lee that Web 2.0 is "what the web was supposed to be all along", a concerted effort is being made by the World Wide Web Consortium (W3C) to bring further semantic meaning to web authoring by streamlining the implementation of interactive elements on a website. The latest specification is HTML5, the next iteration of the markup language used to create web pages and the first update since HTML 4.01 in 1999.

Over the past 10 years, the advent and continued penetration of broadband has meant the web is no longer just a collection of largely text-heavy, hyper-linked pages. The use of audio and video embedded in web pages has grown significantly, together with other multimedia elements. Online news sources frequently use video reports to enhance the main body of text, while the use of Asynchronous JavaScript and XML (AJAX) in web and rich internet applications development has led to the implementation of a richer web experience, including drag-and-drop functionality and offline web applications. 

With that in mind, the current HTML5 draft specification features new semantic element tags to define both video and audio objects, together with a new canvas tag for bitmaps, which are used to store digital images. A host of application programming interface (API) specifications also feature, including drag-and-drop and offline document support.

The W3C published the public working draft of the HTML5 specification in January this year, with full recommendation expected during autumn 2010. But despite being in its infancy, several properties of the draft HTML5 specification are already supported by the latest web browsers. For example, support for the new "video" and "audio" element tags is currently limited to the WebKit layout engine, used by Safari and Google Chrome However, Gecko, the layout engine for internet browser Mozilla FireFox, will offer support for them in v1.9.1, which is currently in beta testing. 

So far, the Trident engine, which powers Microsoft Internet Explorer, only supports the new "embed" tag element, though further recognition of the HTML5 specification will be forthcoming. New APIs, like drag-and-drop, are partially supported by Trident and WebKit, together with many of HTML5’s new global attributes.

Game of tag

One current sticking point for HTML5 is the W3C’s decision to support universal codecs for audio and video, a program that can encode or decode a digital data stream, which will increase the acceptability of the new "audio" and "video" tags amongst web developers. One of the more viable codecs debated as a future baseline audio standard is Ogg Vorbis, from Xiph.org., which has already gained acceptance as an open-source technology in the entertainment industry - although the W3C is yet to announce a final decision.

The streamlining of HTML with the fifth revision, which began life as a multilateral project between Mozilla, Opera, and Apple, will also see a dramatic reduction in the use of the "div" and "span" tags. In addition to the "video" and "audio" elements, HTML5 will see the advent of "header" and "footer" tags, all of which should mean a sharp decrease in the overly-convoluted "div" nests that currently litter web source pages. Beyond the specification of new semantic tags, HTML5 also strengthens the near-universal implementation of cascading style sheets (CSS), a language used to describe the look and formatting of a document, by removing depreciated tags including "font" from the markup specification

Although a full recommendation isn't expected for the next 18 months, HTML5 does reflect the current course of the web, with the mass integration of embedded media forming a keystone of its development. The provision of new tags in the specification also improves the semantics for web developers and the web itself, with the case for a fifth iteration HTML already seen by increased support from the layout engines.