Twenty years ago, in a research establishment in the Swiss Alps, a British-born computer scientist dreamt up a new way for academics to share information around the globe.

Little did he realise that his invention would break out from the confines of academia and give birth to the world wide web.

Two decades on, there are over 200 million websites and over one trillion unique URLs. An astounding 1.6 billion people use the web worldwide, and here in the UK the figure stands at over 70 per cent of the population.

To celebrate this milestone, we're looking back on how and why the web came into being, taking a look at how the web's key technologies have changed since the early '90s and investigating how it has affected our society and culture.

illustrate how vividly things have changed, we'll take a snapshot of the web at four stages in its development – at five, 10, 15 and 20 years old. And to complete our commemoration of the web at 20, we've consulted an expert to find out just how different it could look in another five years' time.

How it all began

The web might have come into being 20 years ago, but that wasn't the start of the internet – far from it. To find the first faltering steps of the information superhighway we have to turn the clock back almost 40 years to the launch of the Advanced Research Projects Agency Network, or ARPANET, which is widely regarded as the evolutionary starting point of the internet we know today. So to see why the web was so revolutionary, we need to investigate how the internet looked back in the late '70s

Some aspects of ARPANET-inspired technology are still with us. ARPANET was the world's first packet switching network, and some of its technologies – including email, FTP (file transfer protocol) for uploading and downloading files, and Usenet, which served a similar purpose to today's web-based newsgroups – were already in existence.

The biggest differences between these systems and their modern-day counterparts lies in the user interface more than the underlying technology. The older services were accessed using typed commands rather than via the now-ubiquitous graphical user interface.

Growing chaos

A more fundamental difference was in the way that people found information. In those pre-web days, that meant either knowing about information sources via word of mouth, email or newsgroups, or perhaps by accessing online library catalogues using the Telnet protocol for running programs on remote computers.

When the internet was tiny, this haphazard system worked (just about), but by the late '80s it was starting to get out of hand. American initiatives such as Gopher (as in 'go for'), WAIS (Wide Area Information Server), Archie and Veronica all did their bit to simplify internet information management, but, as it turned out, they were all doomed to relative obscurity in the light of events taking place across the Atlantic.

In 1989, Tim Berners-Lee, an Oxford-educated computer scientist then working at CERN in Switzerland, proposed a new system for managing online information. Berners-Lee envisaged a system in which hypertext documents could be linked together. By clicking on a 'hot spot' (or link) in one document, the user would be automatically transferred to the document that was referenced in that link. What's more, Berners-Lee suggested that documents could be linked together without any central control or coordination.

The proposal was accepted, and a year later Berners-Lee finished the first ever browser. He named it WorldWideWeb (with no spaces). It ran on a NeXT cube computer, and despite its lack of colour and absence of in-line graphics, the fundamentals would be familiar to today's web users.

Later on, the browser was renamed Nexus to differentiate it from the abstract space that became known as the World Wide Web (with spaces).

Opening the gates

However innovative, who knows whether the concept of globally hyperlinked documents would have taken the world by storm if it wasn't for a couple of political and commercial decisions that took place in those early years.

In March 1993, America's National Science Foundation decided that its network backbone would no longer be restricted to academic institutions. Then, just a month later, CERN made its web technology free for anyone to use. The floodgates were opened – and the world would never be quite the same again.

Five years old

Five years in, the web was just starting to come to the attention of the public, although at this stage it was still mostly computer enthusiasts who were getting involved. One product that was instrumental in bringing the web to the man in the street was called Internet in a Box. Launched by Spry in 1994, it was, to quote the promotional literature, "the first shrink-wrapped package to provide a total solution for PC users to get on the internet". Included in the box was the necessary software to allow Windows to communicate with the internet, a subscription with an ISP and a copy of the Mosaic web browser. Other such packages would soon follow.

The Mosaic web browser really epitomised the web of the mid-'90s, and it's also the product that is widely acknowledged to have first popularised the web. Developed in 1993, the software would later evolve into Netscape Navigator, the descendant of which is still with us today in the form of popular browser Mozilla Firefox.

As with most things related to the internet in those pioneering days, Mosaic was written for the Unix operating system, but other versions were soon released for the Macintosh and, more importantly, the PC. It was the first browser to display images inline with text instead of displaying them in a separate window. In many ways, it still resembles the browser of today.

Mosaic browser

EARLY ANCESTOR: Even as early as 1994, Mosaic could display blue hyperlinks and inline graphics

These early times were also the days of massive growth, even though the numbers pale into insignificance compared to today's figures. In mid-1993 there were just 130 websites worldwide, but by the end of 1994, when the web had reached its fifth birthday, this figure had grown to over 12,000. However, only 18 per cent of these websites had magic '.com' URLs – and the commercialisation of the web was only just beginning.

10 years old

Now that knowledge of the internet was becoming commonplace, software wars were breaking out. Of particular note was the moment that Microsoft introduced Internet Explorer to compete head-on with Netscape Navigator.

In the next five momentous years, no less than five versions of Internet Explorer and four of Netscape Navigator were released. IE finally came out victorious once Microsoft fully integrated it into Windows, but the real beneficiary of those browser wars was the user – the web browsing experience changed out of all recognition.

Northern light search

OLD NEWS: Familiar names like Google had appeared by 1999, but they were yet to oust established search engines such as Northern Light

No longer did the web comprise only static information: dynamic content had entered the scene with a vengeance. Audio and video multimedia content could now be displayed on web pages.

Far more fundamental was support for a range of technologies including the now familiar JavaScript, ActiveX controls and cascading style sheets. This meant that web pages could feature animation and users could fill in forms online and run applications such as games.

By the web's 10th birthday, search engines had also made their presence felt. Although search apps had been around five years earlier, they were small fry then. By now their commercial potential had been recognised, and several sites were vying for the number one spot. At the time, Northern Light and AltaVista were tied with 150 million pages each, but Google was closing in rapidly.

The browser wars and the search engine wars were the tip of the iceberg. The web was now big business and there was no shortage of young companies eager to get a piece of the greatest publishing revolution since the invention of the printing press.

These were the glory days of the 'dot com' companies, with well-known names such as Amazon, eBay, Expedia, Google and Yahoo all appearing. Not all the dotcoms would be successful, though, and another year down the line the bubble would burst, leaving financial catastrophe in its wake.