Columbia Encyclopedia (Bartleby.com)

Dictionary of the History of Ideas

De Imperatoribus Romanis (DIR): An Online Encyclopedia of Roman Emperors

Encyclopedia Britannica / LoveToKnow Free Online Encyclopedia
Based on the eleventh edition of the Encyclopedia Britannica, first published in 1911. The eleventh edition is famous for its detailed and in-depth articles.

Encyclopedia Mythica
An encyclopedia on mythology, folklore, magic. Includes myths from many different cultures.

Encyclopedia of World History (Bartleby.com)

Stanford Encyclopedia of Philosophy (SEP)
A dynamic encyclopedia; each entry is maintained and kept up to date by an expert or group of experts in the field. Entries include extensive bibliographic citations. Note: Table of Contents listings which are not linked indicate articles that have been assigned to be written.

SYMBOLS.com
An online encyclopedia of graphic symbols. More than 2,500 Western signs, arranged into 54 groups according to their graphic characteristics. In 1,600 articles their histories, uses, and meanings are thoroughly discussed. The signs range from ideograms carved in mammoth teeth by Cro-Magnon men, to hobo signs and subway graffiti.