General Encyclopedias
Encyclopedia Britannica «based on the 11th edition from 1911
Encyclopedia Smithsonian «modest collection with links to Smithsonian resources on various subjects
HighBeam «more than 57,000 articles from a variety of sources
Subject Encyclopedias
History
Encyclopedia of World History «2000 publication from Peter N. Stearns and thirty other historians
Math
Wolfram MathWorld «concise mathematics encyclopedia
Music
Encyclopedia of Jazz Musicians «database created by Lewis Porter of Rutgers University
Instrument Encyclopedia «collaborative project from the University of Michigan School of Information and the School of Music
Philosophy
Internet Encyclopedia of Philosophy «founded by James Fieser, Ph.D at the University of Tennessee-Martin
Stanford Encyclopedia of Philosophy «project from Stanford University
Religion
Boston Collaborative Encyclopedia of Western Theology « a project from Boston University
Catholic Encyclopedia «more than 11,000 articles about the Catholic faith from a Catholic perspective
Encyclopedia of Mormonism «from Brigham Young University
Encyclopedia of Religion and Society «from the Hartford Institute of Religion Research
Science
Annotated Physics Encyclopedia «from Igor Ivanov of MIT
Encyclopedia Astronautica «on the history of space exploration
Encyclopedia of Earth «written by experts with an environmental emphasis
Encyclopedia of Standard Planetary Info, Formulae and Constants «written by Chris Barnet of NOAA
Other Encyclopedias
Encyclopedia of Needlework «by Therese de Dillmont
Encyclopedia of Television «from the Museum of Broadcast Communications