AOL NetFind 
http://www.aol.com/netfind/ 
AOL NetFind is an Inktomi-powered search engine targeted at AOL users. Previously, it had been powered by Excite. 

AltaVista 
http://www.altavista.com/ 
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. It also offers a number of features designed to appeal to basic users, such as "Ask AltaVista" results, which come from Ask Jeeves (see below), and directory listings from LookSmart. 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. 

Ask Jeeves 
http://www.askjeeves.com/ 
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. The service went into beta in mid-April 1997 and opened fully on June 1, 1997. Results from Ask Jeeves also appear within

Direct Hit 
http://www.directhit.com/ 
Direct Hit is a company that works with other search engines to refine their results. It does this by monitoring what users click on from the results they see. Sites that get clicked on more than others rise higher in Direct Hit's rankings. Thus, the service dubs itself a "popularity engine." Direct Hit's technology is currently best seen at HotBot. It also refines results at Lycos and is available as an option at LookSmart and MSN Search. The company also crawls the web and refines this database, which can be viewed via the link above. 

Excite 
http://www.excite.com/ 
Excite is one of the most popular search services on the web. It offers a medium-sized index and integrates non-web material such as company information and sports scores into its results, when appropriate. 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. Excite also "powers" the results that appear in AOL NetFind. 

FAST Search 
http://www.alltheweb.com/ 
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. The Norwegian company behind FAST Search also powers the Lycos MP3 search engine. FAST Search launched in May 1999. 

Go / Infoseek 
http://www.go.com/ 
Go is a portal site produced by Infoseek and Disney. It offers portal features such as personalization and free e-mail, plus the search capabilities of the former Infoseek search service, which has now been folded into Go. Searchers will find that Go consistently provides quality results in response to many general and broad searches, thanks to its ESP search algorithm. It also has an impressive human-compiled directory of web sites. Go officially launched in January 1999. It is not related to GoTo, below. The former Infoseek service launched in early 1995. 

GoTo 
http://www.goto.com/ 
Unlike the other search engines (except for AltaVista), GoTo sells its 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, above. 

Google 
http://www.google.com/ 
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. 

HotBot 
http://www.hotbot.com/  
Like AltaVista, HotBot is another favorite among researchers due to its large index of the web and 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. 

Inktomi 
http://www.inktomi.com/ 
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 
http://www.looksmart.com/ 
LookSmart is the closest rival Yahoo has, in terms of being a human-compiled directory of the web. In addition to being a stand-alone service, LookSmart provides directory results to AltaVista and many other partners. AltaVista 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 
http://www.lycos.com/  
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 spidering the web. Lycos also feature another directory of web sites called Lycos Community Guides. Sites are automatically listed in these guides using technology from WiseWire, a company Lycos acquired in early 1998. Lycos is one of the oldest search services, around since May 1994. It began as a project at Carnegie Mellon University. The name Lycos comes from the Latin for "wolf spider." In October 1998, Lycos acquired the competing HotBot search service, which continues to be run separately. 

MSN Search 
http://search.msn.com/ 
Microsoft's MSN Search service is powered by Inktomi. On the MSN portal site, other search engines are also featured, along with directory results.  MSN Search went live in October 1998 with its Inktomi results, although it had existed in various formats and under different names previously. 

Netscape Search 
http://search.netscape.com/ 
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 
http://www.northernlight.com/ 
Northern Light is another favorite search engine among researchers. It features the largest 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 
http://dmoz.org/ 
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 also uses the information for its main service and within Lycos-owned HotBot.

RealNames 
http://www.realnames.com/ 
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. In particular, it is strongly featured in results at AltaVista and Go (Infoseek). 

Snap 
http://www.snap.com/ 
Snap is a human-compiled directory of web sites, supplemented by search results from Inktomi. Like LookSmart, it aims to challenge Yahoo as the champion of categorizing the web. Snap launched in late 1997 and is backed by Cnet and NBC.  

WebCrawler 
http://www.webcrawler.com/ 
WebCrawler has the smallest index of any major search engine on the web -- think of it as Excite Lite. The small index means WebCrawler is not the place to go when seeking obscure or unusual material. However, some people may feel that by having indexed fewer pages, WebCrawler provides less overwhelming results in response to general searches.  WebCrawler opened to the public on April 20, 1994. It was started as a research project at the University of Washington. America Online purchased it in March 1995 and was the online service's preferred search engine until Nov. 1996. That was when Excite, a WebCrawler competitor, acquired the service. Excite continues to run WebCrawler as an independent search engine. 

Yahoo 
http://www.yahoo.com/  
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 over 1 million sites listed. Yahoo also supplements its results with those from Inktomi. If a search fails to find a match within Yahoo's own listings, then matches from Inktomi are displayed. Inktomi matches also appear after all Yahoo matches have first been shown. Yahoo is the oldest major web site directory, having launched in late 1994. 

Credit to http://www.searchenginewatch.com/