Search Engines

• 
  Bing

  Second most popular search engine in the world. Developed by Microsoft.

  bing.com
• 
  Google

  World's leading search engine with trillions of indexed pages.

  google.com - Also see: Google Books, Google Scholar
• 
  Yahoo!

  Widely used search engine powered by Bing.

  search.yahoo.com

Meta Search Engines

• 
  Carrot2

  Open source search results clustering engine that organizes search results into topics.

  carrot2.org
• 
  DuckDuckGo

  Search engine with a clean interface and an emphasis on user privacy.

  duckduckgo.com
• 
  iseek

  Clustering and meta search engine with portals for web, medical, education, and finance.

  iseek.com
• 
  Qwant

  EU-based and privacy-focused search engine with its own indexing engine.

  qwant.com
• 
  Startpage

  Combines the top results of multiple engines, primarily Gigablast and Yandex.

  startpage.com

Academic Search Engines

• 
  BASE

  Operated by Bielefeld University Library, BASE provides an index of over 100M documents.

  base-search.net
• 
  Instagrok

  Turns searches into an interactive concept map that surfaces key facts, relationships, and quizzes.

  instagrok.com
• 
  OpenMD

  Health search engine spanning medical organizations, journals, and databases.

  openmd.com - Also see: Health Site Directory
• 
  RefSeek

  Web and document search engine for students and researchers.

  refseek.com - Also see: Document Search
• 
  ResearchGate

  Searchable library of 135 million scientific publications and questions.

  researchgate.net

International Search Engines

• 
  Baidu

  Leading search engine in China with web, image, and video search options.

  baidu.com
• 
  Yandex

  Russia's most popular search engine for websites, news, and media.

  yandex.com