Just 20 years after it took its first tentative steps into the world, the web has become a revolutionary phenomenon.

Almost 2 billion people are now online globally, and internet connections are now a vital part of international trade, communication and even politics.

Despite the web's rapid growth, however, the technology underpinning it has changed surprisingly little - in many cases remaining more or less the same as when Sir Tim Berners-Lee built the very first web pages in his lab in Switzerland in 1990.

That could all be about to change, however, thanks to a new web technology called HTML5 that promises to shake up the web from top to bottom.