Internet portal Yahoo was set up by two PhD students at California's Stanford University in 1994. According to the company's own folklore, Mr David Filo and Mr Jerry Yang were more interested in compiling lists of their favourite websites than working on their doctorates, and soon had a list of links that had to be categorised and sub-categorised.

Fellow students began accessing the website and, when word spread beyond the confines of the university, Mr Yang and Mr Filo realised the commercial potential of their hobby.

Within six months Yahoo had received one million hits worldwide and by March 1995 the pair had incorporated the business. A year later the company announced an IPO, selling 2.6 million shares at $13 each. It has experienced more or less continuous growth since.

Its success has stemmed from its headstart as the first major directory on the Web, and its easy brand recognition. Based in Sunnyvale, California, Yahoo has remained faithful to its original concept of a Web directory sorted into multiple categories: it's a one-stop shop for every browser's needs.

The company's homepage, the world's most visited website offers a webmail service (second only to Microsoft's Hotmail in global reach), online storage facilities for files and photos, credit cards, a messenger service, chatrooms, Web directories, personalised news sites, online shopping and auctions and a search engine.

Yahoo has succeeded where rivals such as Ask Jeeves struggled to diversify their interests beyond their core operation.

An Irish portal (www.yahoo.ie) was started four years ago, but it was lumped in as Yahoo UK and Ireland and the services are still very British-orientated. The text messaging service included with email accounts is only available to the British mobile networks.

Last year was the sixth successive year of growth for Yahoo, a company that was named after a term coined by Jonathan Swift in Gulliver's Travels. Mr Filo and Mr Yang liked its dictionary definition of "rude, unsophisticated, uncouth".