This is a list of search engines, including web search engines, selection-based search engines, metasearch engines, desktop search tools, and web portals and vertical market websites that have a search facility for online databases.
By content/topic

General

• Baidu (Chinese, Japanese)
• Bing
• Blekko
• Google
• Sogou (Chinese)
• Soso.com (Chinese)
• Volunia
• WireDoo
• Yahoo!
• Yandex.com (Russian)
• Yebol
• Yodao (Chinese)

P2P search engines

• FAROO
• Seeks (Open Source)
• YaCy (Free and fully decentralized)

Metasearch engines

• Brainboost (Public engine no longer exists, acquired by Answers, Inc.)
• ChunkIt! (Public engine no longer exists)
• Yippy (formerly Clusty)
• DeeperWeb
• Dogpile
• Excite
• Harvester42
• HotBot
• Info.com
• Ixquick
• Kayak
• LeapFish (no longer a search engine)
• Mamma
• Metacrawler
• MetaLib (Not a public search engine)
• Mobissimo
• Myriad Search (No longer exists)
• SideStep
• WebCrawler
• Crawler.com

Geographically limited scope

• Accoona, China/United States
• Alleba, Philippines
• Ansearch, Australia/United States/United Kingdom/New Zealand
• Biglobe, Japan
• Daum, Korea
• Goo, Japan
• Guruji.com, India
• Leit.is, Iceland
• Maktoob, Arab World
• Miner.hu, Hungary
• Najdi.si, Slovenia
• Naver, Korea
• Onkosh, Arab World
• Rambler, Russia
• Rediff, India
• SAPO, Portugal/Angola/Cabo Verde/Mozambique
• Search.ch, Switzerland
• Sesam, Norway, Sweden
• Seznam, Czech Republic
• Walla!, Israel
• Yandex.ru, Russia
• Yehey!, Philippines
• ZipLocal, Canada/United States

Accountancy

• IFACnet

Business

• Business.com
• GenieKnows (United States and Canada)
• GlobalSpec
• Nexis (Lexis Nexis)
• Thomasnet (United States)
• Justdial

Enterprise

• AskMeNow: S3 - Semantic Search Solution
• Concept Searching Limited: concept search products
• Coveo: Coveo Enterprise Search platform, Coveo Expresso
• Dieselpoint: Search & Navigation
• dtSearch: dtSearch Engine (SDK), dtSearch Web
• Endeca: Information Access Platform
• Exalead: exalead one:enterprise
• Expert System S.p.A.: Cogito
• Fast Search & Transfer: Enterprise Search Platform (ESP), RetrievalWare (formerly Convera)
• Funnelback: Funnelback Search
• IBM: OmniFind Enterprise Edition
• Inbenta: Inbenta Semantic Search Engine
• ISYS Search Software: ISYS:web, ISYS:sdk
• Jumper 2.0: Universal search powered by Enterprise bookmarking
• Microsoft: SharePoint Search Services
• Northern Light
• Open Text: Hummingbird Search Server, Livelink Search
• Oracle Corporation: Secure Enterprise Search 10g
• SAP: TREX
• TeraText: TeraText Suite
• Vivisimo: Vivisimo Clustering Engine
• X1 Technologies : X1 Enterprise Search
• ZyLAB Technologies: ZyIMAGE Information Access Platform

Food/Recipes

• RecipeBridge: vertical search engine for recipes
• Yummly: semantic recipe search

Mobile/Handheld

• Taganode Local Search Engine
• Taptu: taptu mobile/social search

Job

• Bixee.com (India)
• CareerBuilder.com (USA)
• Craigslist (by city)
• Dice.com (USA)
• Eluta.ca (Canada)
• Hotjobs.com (USA)
• Incruit (Korea)
• Indeed.com (USA)
• LinkUp.com (USA)
• Monster.com (USA), (India)
• Naukri.com (India)
• Yahoo! HotJobs (Countrywise subdomains, International)

Legal

• Google Scholar
• Lexis (Lexis Nexis)
• Manupatra
• Quicklaw
• WestLaw

Medical

• Bing Health
• Bioinformatic Harvester
• EB-eye EMBL-EBI's Search engine
• Entrez (includes Pubmed)
• GenieKnows
• GoPubMed (knowledge-based: GO - GeneOntology and MeSH - Medical Subject Headings)
• Healia
• Healthline
• Nextbio (Life Science Search Engine)
• PubGene
• Quertle (Semantic search of the biomedical literature)
• Searchmedica
• VADLO (Life Sciences Search Engine)
• WebMD

News

• Bing News
• Daylife
• Google News
• MagPortal
• Newslookup
• Nexis (Lexis Nexis)
• Topix.net
• Yahoo! News

People

• Comfibook
• Ex.plode.us
• InfoSpace
• PeekYou
• Spock
• Spokeo
• Wink
• Worldwide Helpers
• Zabasearch.com
• ZoomInfo

Real estate / property

• Fizber.com
• HotPads.com
• Realtor.com
• Redfin
• Rightmove
• Zillow.com

Television

• TV Genius

Video Games

• Wazap (Japan)

By information type

Search engines dedicated to a specific kind of information
Forum

• Omgili

Blog

• Amatomu
• IceRocket (Defunct)
• Regator
• Technorati

Multimedia

• Bing Videos
• blinkx
• FindSounds
• Google Video
• Munax's PlayAudioVideo
• Picsearch
• Pixsta
• Podscope
• ScienceStage
• SeeqPod
• Songza
• TinEye
• TV Genius
• Veveo
• Yahoo! Video
• YouTube

Source code

• Google Code Search
• JExamples
• Koders
• Krugle

BitTorrent

These search engines work across the BitTorrent protocol.

• FlixFlux
• Isohunt
• Mininova
• The Pirate Bay
• TorrentSpy
• Torrentz

Email

• Lookeen
• TEK

Maps

• Bing Maps
• Géoportail
• Google Maps
• MapQuest
• Nokia_Maps
• OpenStreetMap
• WikiMapia
• Yahoo! Maps

Price

• Bing Shopping
• Google Shopping (formerly Google Product Search and Froogle)
• Kelkoo
• MySimon
• PriceGrabber
• PriceRunner
• PriceSCAN
• Pronto.com
• Shopping.com
• ShopWiki
• Shopzilla (also operates Bizrate)
• SwoopThat.com
• TheFind.com
• Wishabi

Question and answer

Human answers

• Answers.com
• Ask Me Help Desk
• DeeperWeb
• eHow
• Quora
• Stack Overflow/Stack Exchange Network
• Uclue
• wikiHow
• Yahoo! Answers

Automatic answers

• AskMeNow
• BrainBoost
• True Knowledge
• Wolfram Alpha

Natural language

• Ask.com
• Bing (Semantic ability is powered by Powerset)
• BrainBoost
• hakia
• Lexxe
• Powerset

By model

Privacy search engines

• DuckDuckGo
• Scroogle Scraper

Open source search engines

• DataparkSearch
• Egothor
• Grub
• ht://Dig
• Isearch
• Lemur Toolkit & Indri Search Engine
• Lucene
• mnoGoSearch
• MozDex
• Namazu
• Nutch
• Recoll
• Sciencenet (for scientific knowledge, based on YaCy technology)
• Seeks
• Sphinx
• SWISH-E
• Terrier Search Engine
• Wikia Search
• Xapian
• YaCy
• Zettair

Semantic browsing engines

• Hakia
• Yebol

Social search engines

• ChaCha Search
• Delver
• Eurekster
• Mahalo.com
• OneRiot
• Rollyo
• SearchTeam
• Sproose
• Trexy
• Wink provides web search by analyzing user contributions such as bookmarks and feedback

Visual search engines

• ChunkIt!
• Grokker
• Pixsta
• PubGene
• TinEye
• Viewzi
• Macroglossa

Search appliances

• Google: Google Search Appliance

Usenet

• Google Groups (formerly Deja News)

Based on

Google

• AOL Search
• CompuServe Search
• Groovle
• MySpace Search
• Netscape
• Ripple

Yahoo!

• AltaVista
• Ecocho
• Everyclick (formerly based on Ask.com)
• Forestle (an ecologically motivated site supporting sustainable rain forests - formerly based on Google)
• GoodSearch
• Rectifi

Bing

• A9.com
• Alexa Internet
• Ciao!
• Ecosia
• Facebook
• Ms. Dewey
• Yahoo! Search

Ask.com

• Hakia (semantic search)
• iWon
• Lycos
• Teoma

Acquired or defunct search engines

• AlltheWeb
• BRS/Search (now OpenText Livelink ECM Discovery Server)
• Btjunkie
• Cuil
• Direct Hit Technologies (acquired by Ask Jeeves in January, 2000)
• Google Answers
• IBM STAIRS
• Infoseek
• Inktomi
• Kartoo
• Lotus Magellan
• Overture.com (formerly GoTo.com, now Yahoo! Search Marketing)
• PubSub
• RetrievalWare (acquired by Fast Search & Transfer and now owned by Microsoft)
• Scroogle
• Singingfish
• Speechbot
• Sphere
• Tafiti
• Wikia Search
• WiseNut
• World Wide Web Worm

Source:Wikipedia