INTERNET SEARCH ENGINES
Google
Largest database of webpages
Yahoo!
Popular search engine and subject directory
Bing
Popular search engine run by Microsoft
META-SEARCH ENGINES
Meta-search engines compile and sort results from multiple search engines.
Dogpile
Meta-search engine which brings together top results from Google, Yahoo!, and Bing
AllPlus
Meta-search engine which compiles top results from search engines like Google, Yahoo!, MSN Live, and Ask.com
CONTENT-SPECIFIC SEARCH ENGINES
Google Scholar
Google's search engine for scholarly sources
SCIRUS
Scientific research search engine - includes links to journal articles, as well as to scientists' homepages, courseware, institutional repositories and other related websites
Search.USA.gov
U.S. government's official search engine - includes information from federal, state, local, territorial and tribal websites
SUBJECT DIRECTORIES
Subject directories are resources for specific topics.
Academic Info Online Subject Guides
Large collection of subject guides for academic disciplines and specific research topics - list both online resources and printed reference works
Best Information on the Net (St. Ambrose University Library)
Online sources organized by academic major, popular paper topic, or alphabetical order
Complete Planet
Search engine and web directory, retrieves records through both databases and search engines and locates "deep web" records difficult to find through other search engines
INFOMINE
Virtual library of university-level internet resources, created by librarians and researchers
Intute
Provides access to a variety of web resources for research
Internet Public Library (IPL2)
Collections of resources from the Internet Public Library (IPL) and the Librarians' Internet Index (LII)
Open Directory Project
Largest human-edited web directory, created and maintained by volunteer editors across the globe
Virtual Reference Shelf (Library of Congress)
Selected high-quality resources for research organized by subjects and categories