AOL Search
AOL Search allows its members to search across the web and AOL's own content from one place. The "external" version, listed above, does not list AOL content. The main listings for categories and web sites come from the Open Directory (see below). Inktomi (see below) also provides crawler-based results, as backup to the directory information. Before the launch of AOL Search in October 1999, the AOL search service was Excite-powered AOL NetFind.

AltaVista
AltaVista is consistently one of the largest search engines on the web, in terms of pages indexed. Its comprehensive coverage and wide range of power searching commands makes it a particular favorite among researchers. In addition to crawler-based web page matches, it also offers news search, shopping search, multimedia search and human-powered directory results from LookSmart (see below). AltaVista opened in December 1995. It was owned by Digital, then run by Compaq (which purchased Digital in 1998), then spun off into a separate company which is now controlled by CMGI. AltaVista also operates the Raging Search service, below.

Ask Jeeves
Ask Jeeves is a human-powered search service that aims to direct you to the exact page that answers your question. If it fails to find a match within its own database, then it will provide matching web pages from various search engines.

Direct Hit
Direct Hit measures what people click on in the search results presented at its own site and at its partner sites, such as HotBot. Sites that get clicked on more than others rise higher in Direct Hit's rankings. Thus, the service dubs itself a "popularity engine." Aside from running its own web site, Direct Hit provides the main results which appear at HotBot (see below) and is available as an option to searchers at MSN Search. Direct Hit is owned by Ask Jeeves (above). See the Using Direct Hit Results page to learn more about Direct Hit.

Excite
Excite offers a medium-sized crawler-based web page index, as well as access to human-powered directory results from LookSmart. Excite was launched in late 1995. It grew quickly in prominence and consumed two of its competitors, Magellan in July 1996, and WebCrawler in November 1996. These continue to run as separate services.

FAST Search
Formerly called All The Web, FAST Search aims to index the entire web. It was the first search engine to break the 200 million web page index milestone and consistently has one of the largest indexes of the web. The Norwegian company behind FAST Search also powers some of the results that appear at Lycos (see below). FAST Search launched in May 1999.

GoTo
Unlike the other major search engines, GoTo sells its main listings. Companies can pay money to be placed higher in the search results, which GoTo feels improves relevancy. Non-paid results come from Inktomi. GoTo launched in 1997 and incorporated the former University of Colorado-based World Wide Web Worm. In February 1998, it shifted to its current pay-for-placement model and soon after replaced the WWW Worm with Inktomi for its non-paid listings. GoTo is not related to Go (Infoseek). Paid listing from GoTo also appear on other major search engines, including AltaVista, AOL Search, Lycos, HotBot and Netscape Search.

Google
Google is a search engine that makes heavy use of link popularity as a primary way to rank web sites. This can be especially helpful in finding good sites in response to general searches such as "cars" and "travel," because users across the web have in essence voted for good sites by linking to them. The system works so well that Google has gained wide-spread praise for its high relevancy. Google also has a huge index of the web and provides some results to Yahoo and Netscape Search.

HotBot
HotBot is a favorite among researchers due to its many power searching features. In most cases, HotBot's first page of results comes from the Direct Hit service (see above), and then secondary results come from the Inktomi search engine, which is also used by other services. It gets its directory information from the Open Directory project (see below). HotBot launched in May 1996 as Wired Digital's entry into the search engine market. Lycos purchased Wired Digital in October 1998 and continues to run HotBot as a separate search service.

IWon
Backed by US television network CBS, iWon has a directory of web sites generated automatically by Inktomi, which also provides its more traditional crawler-based results. iWon gives away daily, weekly and monthly prizes in a marketing model unique among the major services. It launched in Fall 1999.

Inktomi
Originally, there was an Inktomi search engine at UC Berkeley. The creators then formed their own company with the same name and created a new Inktomi index, which was first used to power HotBot. Now the Inktomi index also powers several other services. All of them tap into the same index, though results may be slightly different. This is because Inktomi provides ways for its partners to use a common index yet distinguish themselves. There is no way to query the Inktomi index directly, as it is only made available through Inktomi's partners with whatever filters and ranking tweaks they may apply.

LookSmart
LookSmart is a human-compiled directory of web sites. In addition to being a stand-alone service, LookSmart provides directory results to MSN Search, Excite and many other partners. Inktomi provides LookSmart with search results when a search fails to find a match from among LookSmart's reviews. LookSmart launched independently in October 1996, was backed by Reader's Digest for about a year, and then company executives bought back control of the service.

Lycos
Lycos started out as a search engine, depending on listings that came from spidering the web. In April 1999, it shifted to a directory model similar to Yahoo. Its main listings come from the Open Directory project, and then secondary results come from the FAST Search engine. Some Direct Hit results are also used. In October 1998, Lycos acquired the competing HotBot search service, which continues to be run separately.

MSN Search
Microsoft's MSN Search service is a LookSmart-powered directory of web sites, with secondary results that come from Inktomi. RealNames and Direct Hit data is also made available.

NBCi
NBCi is a human-compiled directory of web sites, supplemented by search results from Inktomi. It was formerly known as Snap but had a name change in late 2000. Backed by US television network NBC, the site's future is in doubt, as NBC announced wide-spread layoffs in April 2001.

Netscape Search
Netscape Search's results come primarily from the Open Directory and Netscape's own "Smart Browsing" database, which does an excellent job of listing "official" web sites. Secondary results come from Google. At the Netscape Netcenter portal site, other search engines are also featured.

Northern Light
Northern Light is another favorite search engine among researchers. It features a large index of the web, along with the ability to cluster documents by topic. Northern Light also has a set of "special collection" documents that are not readily accessible to search engine spiders. There are documents from thousands of sources, including newswires, magazines and databases. Searching these documents is free, but there is a charge of up to $4 to view them. There is no charge to view documents on the public web -- only for those within the special collection. Northern Light opened to general use in August 1997.

Open Directory
The Open Directory uses volunteer editors to catalog the web. Formerly known as NewHoo, it was launched in June 1998. It was acquired by Netscape in November 1998, and the company pledged that anyone would be able to use information from the directory through an open license arrangement. Netscape itself was the first licensee. Lycos and AOL Search also make heavy use of Open Directory data.

Raging Search
Operated by AltaVista, Raging Search uses the same core index as AltaVista and virtually the same ranking algorithms. Why use it? AltaVista offers it for those who want fast search results, with no portal features getting in the way.

RealNames
The RealNames system is meant to be an easier-to-use alternative to the current web site addressing system. Those with RealNames-enabled browsers can enter a word like "Nike" to reach the Nike web site. To date, RealNames has had its biggest success through search engine partnerships. See the Using RealNames Links page for more information about RealNames.

Yahoo
Yahoo is the web's most popular search service and has a well-deserved reputation for helping people find information easily. The secret to Yahoo's success is human beings. It is the largest human-compiled guide to the web, employing about 150 editors in an effort to categorize the web. Yahoo has well over 1 million sites listed. Yahoo also supplements its results with those from Google (beginning in July 2000, when Google takes over from Inktomi). If a search fails to find a match within Yahoo's own listings, then matches from Google are displayed. Google matches also appear after all Yahoo matches have first been shown. Yahoo is the oldest major web site directory, having launched in late 1994.

WebTop
WebTop is a crawler-based search engine that claims an extremely large index. In addition to listing web pages, WebTop also provides information from news sources, company information and WAP-related content in its search results. The company also offers the WebCheck tool (formerly called k-check), which is an Alexa-like search and discovery tool. WebTop is backed by Bright Station, the company that acquired some search technology and other resources from the former Dialog Corporation. The Dialog search service itself is now owned by a different company, the Thomson Corporation.