Encyclopedias:
Encyclopedia Britannica
Encyclopedia Britannica (1911 edition)
Columbia Encyclopedia
Encarta
Encyberpedia
EncycloZine: Books and Knowledge
Encyclopedia.com
Infoplease.com
Informationsphere.com
My Virtual
Probert
Wikipedia
World Book Encyclopedia
Dictionaries:
Merriam-Webster Online Dictionary
yourDictionary.com
Encarta
Wordsmyth
The American HeritageŽ Dictionary of the English Language
Infoplease
Dictionary.com
Webster's Dictionary (1913 edition; Revised, Unabridged)
RhymeZone
AllWords.com
Webster's Dictionary (1828 edition)
WordNet 2.0 Vocabulary Helper
LookWayup
Webster's Online Dictionary (The Rosetta Edition)
The Compact Oxford English Dictionary
Open Dictionary
TheFreeDictionary.com
WordWeb Online
hyperdictionary
elook.org
English Dictionary
Wiktionary
Maps & Atlases:
National Geographic
The Atlas of Canada
InfoPlease Atlas
Atlapedia Online
All the World's Maps
Library of Congress (Map Collections)
University of Iowa Center for Global & Regional Environmental Research
The Global Landforms Database
Color Landform Atlas of the United States
Expedia.com
WorldAtlas.com
MapQuest
Holt, Rinehart & Winston World Atlas
The Lonely Planet
Perry-Castaņeda Library Map Collection
The David Rumsey Historical Map Collection
Thesauruses:
Merriam-Webster Online Thesaurus
Roget's Thesaurus (1911 version)
Roget's II: The New Thesaurus (1995)
Encarta
Infoplease
Thesaurus.com
WordWeb Online
Translation Programs:
Foreignword.com
FreeTranslation.com