• Britannica Online
• The Borderlands Encyclopedia
  A Digital Educational Resource on Contemporary United States-Mexico Border Issues (University of Texas at El Paso).
• Catholic Encyclopedia
• Encyberpedia
• Encyclopedia.Com
  A free service from the subscription service "Electric Library." More than 17,000 articles from the Concise Columbia Electronic Encylopedia(3rd ed) have hyperlinks to related articles as well as references to articles within the Electric Library database.
• Encyclopedia Smithsonian
• The Internet Encyclopedia of Philosophy
• PC Webopedia
  A dictionary/encyclopedia about personal computers.

(updated 10/8/2015)