Google, founded in 1998 by two Stanford University graduate students, Larry Page and Sergey Brin, quickly became the web's leading search engine because it was easy to use and delivered high-quality results.

Rather than relying on users to frame intelligent searches to find what they want, Google's page-rank system massages the results to push the best sites to the top. Quality is decided by the number of other good sites that link to the same content.

Now Google also provides other options on its front page to search for images, news stories, Usenet postings (under Groups), shopping sites (under Froogle) and, in the US, for local companies. PC users can also install a toolbar that adds Google to their browser, and download desktop search software that enables Google to search their hard drive.

There are further options, not on the front page, to search mail order catalogues, and computer-related topics (Apple Macintosh, BSD Unix, Linux, Microsoft), US universities and scholarly publications.

Google is now expanding beyond search and also offers email (Gmail), a blogging service (Blogger), social networking (Orkut), and photo album software (Picasa). Most are useful, but in general, are not integrated to work together.

Yahoo

Yahoo started 11 years ago as a simple directory of websites compiled by two Stanford University graduate students, David Filo and Jerry Yang. It soon became the most prominent site on the web, and expanded rapidly into a portal.

It now offers email, instant messaging, a groups system (not related to Usenet), auctions, games, online stores, photo albums, home pages on the web (through GeoCities), and too many other features to mention. Many of these have become increasingly hard to find. The hierarchical directory that used to make up the front page has disappeared, and been replaced by a Google-like search box.

Yahoo's options are: Web, Images, Video, Directory, Local, News, and Products. Yahoo used to get its web search results from Google but it has taken over a number of search engines, including AltaVista, and now supplies its own.

If you run a web search on Yahoo, the results look almost identical to Google, and many of the top sites are the same. Yahoo's advantage, as a portal, is that millions of users go there for reasons that have nothing to do with search, but if they need to look something up, they may as well use Yahoo rather than go to Google.

MSN Search

MSN, the Microsoft Network, was launched in 1995 as a rival to AOL. It added Hotmail, instant messaging, shopping and other services as it grew into a portal, and in July 2000, it became the leading web destination, with more than 200m visitors a month. Two years ago, Microsoft decided that MSN's search should be powered by Microsoft technology, and this was finally released in 21 countries in 10 languages on February 1.

Microsoft's offerings are: Web, News, Images, Desktop, and Encarta. It also has a Near Me button for local searches. The results pages look like Google's but adverts are more prominent. As with Google and Yahoo, the toolbar and desktop search software must be downloaded separately.

Unadjusted searches at MSN are rarely better than Google and sometimes much worse. Most of its usage is therefore most likely to come from people who are on the MSN site for other reasons, or are searching from Microsoft's Internet Explorer browser, where it is the default.

MSN Search does have a drop-down tool, Search Builder, which includes sliders that let you adjust the settings for sites that are more popular or have been updated recently. However, these are so cumbersome to use, it seems few will bother.

Golden oldies

Ask Jeeves (www.ask.com) is one of the biggest engines outside the top table, and claims to be most people's "second favourite engine". The original concept of using natural language ("where can I find bike shops in Glasgow?") still holds true, although it also caters for keyword searching. The hard work is done by the Teoma engine (www.teoma.com), which Jeeves acquired in 2000. Both give clean results, including image and related search options, and Jeeves also offers MyJeeves, which remembers your searches and lets you save important ones.

Other long-standing search names are still going, though most have been bought out by larger rivals or exist in radically different forms. Pioneer AltaVista (www.altavista.com) was bought out by a series of small firms until it was hoovered up by Yahoo, and it now uses Yahoo results, though it still boasts one of the web's best translators, BabelFish ( babelfish.altavista.com). Other engines including Inktomi have also been consumed by the Yahoo brand.

One of the web's earliest search successes, Lycos (www.lycos.com), is still around, though it, too, has changed hands many times. It now works in tandem with Hotbot (www.hotbot.com), a metasearch site that pulls results from across several engines to produce aggregated - and theoretically better - results.

Dogpile (www.dogpile.com) is probably the best-known metasearch engine, and draws results from Jeeves, Google, Yahoo and others. It pulls answers from these and removes duplicates, but sometimes misses some of the more idiosyncratic results. It also searches across images, audio, video and news. If you find the results aren't quite your cup of tea, you could turn to MetaCrawler (www.metacrawler.com), which is also owned by Dogpile's parent company, Infospace. Metacrawler was launched in 1994, so it has a long track record, and it produces filtered results from a familiar range of sources.

Clustering

Several of the lower league search engines use a technique known as clustering to help users filter out the best results. This intelligently divides a morass of answers into categories, to help users weed out unwanted pages - particularly useful if you get thousands of results on your keywords.

Clusty (www.clusty.com) is still in beta-testing mode, but combines Google-like search functions with clustering options. A search for "Guardian Online", for example, pro duced clusters including newspapers, politics, journalism, entertainment, books and angels. You can build categories based on either topic, source or URL, and the news and image searches seem fairly accurate, even if they sometimes return fewer results than you might need.

Australian-based Mooter (www.mooter.com) has a more visual approach, presenting clusters as a spider diagram, and shows a more traditional list when you click on your chosen category - but by the time you get to the results, they seem much the same as other engines.

Kartoo www.kartoo.com) takes the visual option further by drawing Flash "maps" of search results. While visually interesting, it can be cumbersome and seems to throw up a lot of commercial results.

Regular and real time

Other sites have chosen different ways to change Google's search paradigm. Some have opted for more regular - or even real-time - searching, taking results from the web as they happen rather than relying on an irregularly updated library of results.

Daypop (www.daypop.com) trawls news sites and weblogs at least once a day, producing good results, while Technorati.com (www.technorati.com) applies itself purely to weblogs but picks up new pages within minutes of them being published. The basic search is adequate, though it sometimes suffers from time outs. The recently launched "tags" function incorporates blog categories, social bookmarking site del.icio.us and photo-sharing service Flickr to create ad-hoc keyword homepages.

Local searches

Some search firms focus on geographical niches, favouring local results to offer what could be more appropriate answers. Several target the British market, including UKWizz (www.ukwizz.com), which looks quite basic and struggles to compete with Google's local search (www.google.co.uk).

Newsnow (www.newsnow.co.uk), a British-based news searcher, sifts through headlines on news stories and categorises them by age. It is very good for basic searches ("Beckham", for example) but you have to pay to search for multiword phrases or inside the full text of an article.

Exalead, which is still in beta, ( http://beta.exalead.com ) is a well-designed attempt to provide as many search options as possible, including geographically based ones. It also includes audio and video searching, limited clustering and the ability to search for different document types - all without cluttering the interface.

Honourable mentions

Blinkx (www.blinkx.com) drops keyword search in favour of clever artifical intelligence to find what you're looking for. The interface is clunky, but it draws results from the web, your desktop and other sources.

Icerocket (< a href="http://www.icerocket.com">www.icerocket.com) is quite similar to the big engines, but provides a screenshot of the page the result comes from, and searches both blogs and photographs within blogs - though that seems limited.

Singing Fish (www.singingfish.com) focuses on audio and video search. It is not perfect and is unlikely to give you huge numbers of results (just 10 for "Eminem Mosh", for example) but it is customisable and has a parental filter.

Websbiggest (www.websbiggest.com) ranks pages by the amount of traffic they get, while Looksmart (www.looksmart.com), a survivor of the early days, focuses on being a portal, offering little to the search melee.

Amazon-owned A9 (www.a9.com) organises and recalls searches easily (handy if you can't remember how you found that website last Saturday), but the basic results are provided by Google. It links up with Amazon.com and the Internet Movie Database, making it useful for searching across books and movies.