Search engine
The term search engine refers to a search application that provides links to web pages and other relevant information on the Web (or the Internet in general) in response to a user's query. Users submit their queries through a web browser or a mobile app, and the results page generally displays a collection of hyperlinks together with brief descriptions and relevant images. Users also have the option of limiting a search to specific types of results, such as images, videos, or news.
For a search provider, its engine is part of a distributed computing system that can encompass many data centers throughout the world. The speed and accuracy of an engine's response to a query are based on a complex system of indexing that is continuously updated by automated web crawlers. This can include data mining the files and databases stored on web servers, although some content is not accessible to crawlers.
There have been many search engines since the dawn of the Web in the 1990s; Google Search became the dominant one in the 2000s and has remained so. As of May 2025, according to StatCounter, Google held approximately 89–90 % of the worldwide search share, with competitors trailing far behind: Bing (~4 %), Yandex (~2.5 %), Yahoo! (~1.3 %), DuckDuckGo (~0.8 %), and Baidu (~0.7 %).[1] May 2025 marked the first time in over a decade that Google's share has fallen below the 90% threshold.
Because of its market share, the discipline of websites improving their visibility in search results, known as marketing and optimization, has historically largely focused on Google.
History
[edit]| Year | Engine | Current status |
|---|---|---|
| 1993 | W3Catalog | Inactive |
| ALIWEB | Inactive | |
| JumpStation | Inactive | |
| WWW Worm | Inactive | |
| 1994 | WebCrawler | Active |
| Go.com | Inactive, redirects to Disney | |
| Lycos | Active | |
| Infoseek | Inactive, redirects to Disney | |
| 1995 | Yahoo! Search | Active, initially a search function for Yahoo! Directory |
| Daum | Active | |
| Search.ch | Active | |
| Magellan | Inactive | |
| Excite | Active | |
| MetaCrawler | Active | |
| AltaVista | Inactive, acquired by Yahoo! in 2003, since 2013 redirects to Yahoo! | |
| SAPO | Active | |
| 1996 | RankDex | Inactive, incorporated into Baidu in 2000 |
| Dogpile | Active | |
| HotBot | Inactive (used Inktomi search technology) | |
| Ask Jeeves | Inactive | |
| 1997 | AOL NetFind | Active (rebranded AOL Search since 1999) |
| goo.ne.jp | Active | |
| Northern Light | Inactive | |
| Yandex | Active | |
| 1998 | Active | |
| Ixquick | Active as Startpage.com | |
| MSN Search | Active as Bing | |
| empas | Inactive (merged with NATE) | |
| 1999 | AlltheWeb | Inactive (URL redirected to Yahoo!) |
| GenieKnows | Inactive, rebranded Yellowee (was redirecting to justlocalbusiness.com) | |
| Naver | Active | |
| Teoma | Inactive (redirect to Ask.com) | |
| 2000 | Baidu | Active |
| Exalead | Inactive | |
| Gigablast | Inactive | |
| 2001 | Kartoo | Inactive |
| 2003 | Info.com | Active |
| 2004 | A9.com | Inactive |
| Clusty | Active, Yippy, previously Clusty, now owns Togoda.com | |
| Mojeek | Active | |
| Sogou | Active | |
| 2005 | SearchMe | Inactive |
| 2006 | Soso | Inactive, merged with Sogou |
| Quaero | Inactive | |
| Search.com | Active | |
| ChaCha | Inactive | |
| Ask.com | Inactive | |
| Live Search | Active as Bing, rebranded MSN Search | |
| 2007 | wikiseek | Inactive |
| Sproose | Inactive | |
| Wikia Search | Inactive | |
| Blackle.com | Active, Google Search | |
| 2008 | Powerset | Inactive (redirects to Bing) |
| Picollator | Inactive | |
| Viewzi | Inactive | |
| LeapFish | Inactive | |
| Forestle | Inactive (redirects to Ecosia) | |
| DuckDuckGo | Active | |
| TinEye | Active | |
| 2009 | Bing | Active, rebranded Live Search |
| Yebol | Inactive | |
| Scout (Goby) | Active | |
| NATE | Active | |
| Ecosia | Active | |
| Startpage.com | Active, sister engine of Ixquick | |
| 2010 | Blekko | Inactive, sold to IBM |
| Cuil | Inactive | |
| Yandex (English) | Active | |
| Parsijoo | Active | |
| 2011 | YaCy | Active, P2P |
| 2012 | Volunia | Inactive |
| 2013 | Qwant | Active |
| 2014 | Egerin | Active, Kurdish / Sorani |
| Swisscows | Active | |
| Searx | Inactive | |
| 2015 | Yooz | Inactive |
| Cliqz | Inactive | |
| 2016 | Kiddle | Active, Google Search |
| 2017 | Presearch | Inactive |
| 2018 | Kagi | Active |
| 2020 | Petal | Active |
| 2021 | Brave Search | Active |
| You.com | Active | |
| SearXNG | Active, Fork of Searx | |
| 2022 | Perplexity | Active |
Pre-1990s
[edit]In 1945, Vannevar Bush described an information retrieval system that would allow a user to access a great expanse of information, all at a single desk, which he called a memex.[2] He described this system in an article titled "As We May Think" in The Atlantic Monthly.[3] The memex was intended to give a user the capability to overcome the ever-increasing difficulty of locating information in ever-growing centralized indices of scientific work. Vannevar Bush envisioned libraries of research with connected annotations, which are similar to modern hyperlinks.[4]
Link analysis eventually became a crucial component of search engines through algorithms such as Hyper Search and PageRank.[5][6]
1990s: Birth of search engines
[edit]The first internet search engines predate the debut of the Web in December 1990: WHOIS user search dates back to 1982,[7] and the Knowbot Information Service multi-network user search was first implemented in 1989.[8] The first well-documented search engine that searched content files, namely FTP files, was Archie, which debuted on 10 September 1990.[9]
Before September 1993, the World Wide Web was entirely indexed by hand. There was a list of webservers edited by Tim Berners-Lee and hosted on the CERN webserver. One snapshot of the list in 1992 remains,[10] but as more and more web servers went online the central list could no longer keep up. On the NCSA site, new servers were announced under the title "What's New!".[11]
The first tool used for searching content (as opposed to users) on the Internet was Archie.[12] The name stands for "archive" without the "v".[13] It was created by Alan Emtage,[13][14][15][16] computer science student at McGill University in Montreal, Quebec, Canada. The program downloaded the directory listings of all the files located on public anonymous FTP (File Transfer Protocol) sites, creating a searchable database of file names; however, Archie Search Engine did not index the contents of these sites since the amount of data was so limited it could be readily searched manually.
The rise of Gopher (created in 1991 by Mark McCahill at the University of Minnesota) led to two new search programs, Veronica and Jughead. Like Archie, they searched the file names and titles stored in Gopher index systems. Veronica (Very Easy Rodent-Oriented Net-wide Index to Computerized Archives) provided a keyword search of most Gopher menu titles in the entire Gopher listings. Jughead (Jonzy's Universal Gopher Hierarchy Excavation And Display) was a tool for obtaining menu information from specific Gopher servers. While the name of the search engine "Archie Search Engine" was not a reference to the Archie comic book series, "Veronica" and "Jughead" are characters in the series, thus referencing their predecessor.
In the summer of 1993, no search engine existed for the web, though numerous specialized catalogs were maintained by hand. Oscar Nierstrasz at the University of Geneva wrote a series of Perl scripts that periodically mirrored these pages and rewrote them into a standard format. This formed the basis for W3Catalog, the web's first primitive search engine, released on September 2, 1993.[17]
In June 1993, Matthew Gray, then at MIT, produced what was probably the first web robot, the Perl-based World Wide Web Wanderer, and used it to generate an index called "Wandex". The purpose of the Wanderer was to measure the size of the World Wide Web, which it did until late 1995. The web's second search engine Aliweb appeared in November 1993. Aliweb did not use a web robot, but instead depended on being notified by website administrators of the existence at each site of an index file in a particular format.
JumpStation (created in December 1993[18] by Jonathon Fletcher) used a web robot to find web pages and to build its index, and used a web form as the interface to its query program. It was thus the first