- Wikipedia
 - Wikipedia is a free, open content, community-built encyclopedia with thousands of articles on topics from A to Z. Available in dozens of languages. - Encyclopedia Britannica
- Official site of the Encyclopedia Britannica, one of the world's best-known reference books. Find short encyclopedia entries and definitions, or register for complete access.
- Wikipedia in English
- English-language version of Wikipedia, the online encyclopedia built and edited by users. Find encyclopedia entries on almost any topic, or click for a random Wikipedia article.
- Encyclopedia.com
- Find encyclopedia entries from the Columbia Encyclopedia, with links to newspaper and magazine articles, pictures, and maps. From Highbeam Research.
- Infoplease
- Online encyclopedia entries, dictionary definitions, and thesaurus help from Infoplease, covering topics from astrophysics to Zimbabwe.
- Answers.com
- Get answers from a variety of encyclopaedias, dictionaries, glossaries, and atlases with Answers.com, an online reference source.
- Encarta
- Online encyclopedia, dictionary, atlas, and other reference tools from MSN Encarta. Find encyclopedia entries, dictionary definitions, and homework help.
- 1911 Encyclopedia Britannica
- Searchable online version of the 1911 Encyclopedia Britannica, containing 29 volumes and articles written by more than 1500 authors on topics from A to Z.
- Everything2
- User-created encyclopedia, web directory, and knowledge web. Everything2 offers definitions, articles, and writeups by readers about anything and everything.
- EncycloZine
- Online store and encyclopedia. FInd information and products on topics like art, technology, history, science, sport, and space.
- Columbia Encyclopedia, Sixth Edition
- Online version of the Columbia Encyclopedia, including thousands of searchable encyclopedia entries and topics.
- Citizendium
- Project to create a user-created encyclopedia that aims to improve on the Wikipedia model by adding 'gentle expert oversight' and requiring contributors to use their real names.
- Article Insider
- Community where real-life specialists share their knowledge about a wide variety of popular topics.
- Probert Encyclopaedia
- Online encyclopedia specialising in short, inter-linked articles about anything from famous actors to "psychological phobias.
- Rudiments of Wisdom Encyclopaedia
- Cartoon, with A to Z drawings by Tim Hunkin illustrating topics like animals, geography, science, and history.
- Project Galactic Guide
- Spoof encyclopedia meant to guide and misguide its readers in matters of life, death, and finding a parking space anywhere in the Universe, in the style of the Hitchhiker's Guide to the Galaxy.
- Yahoo! Reference
- Find an online encyclopedia, quotations, and other fact-finding tools at Yahoo! Reference. Search for dictionary definitions, spelling help, thesaurus synonyms, maps, flags, and other answers.
- BambooWeb Dictionary
- Online dictionary and encyclopedia providing articles and information on a wide variety of topics. Browse encyclopedia entries by subject, or search for information by key words.
- Fixed Reference: Snapshots of Wikipedia
- Offers periodic fixed snapshot copies of Wikipedia, the collective online encyclopedia, allowing safe reference and linking without talk pages.
- Encyclopedia of Diderot & d'Alembert - Collaborative Translation Project
- English translation of the articles from the Encyclopédie edited by Denis Diderot and Jean le Rond d'Alembert in the 18th century.
- 1902 Encyclopedia
- Articles and illustrations from the Encyclopaedia Britannica, 9th Edition (1875) and 10th Edition (1902). Searchable by keyword and browsable by subject index.
 Britannica India@
- Encyclocentral
- Features a collection of original, informative, and authoritative articles on a wide variety of subjects.
- Freebase
- An open, shared database of the world's knowledge.
- Halfvalue.com: Answers
- Get answers from a variety of encyclopaedias, dictionaries, and reference sources at Halfvalue.com.
- Knol
- A platform for user-generated knowledge. Knol encourages authors to write authoritative articles on specific subjects.
|
