General Reference Resources

A free version on the web that includes 80,000 general subject, cross-referenced entries. Easily searchable or browsable.

A free web encyclopedia of life on Earth including information about each of the Earth's 1.8 million known species.

A free version of Houghton Mifflin's encyclopedia of ancient, medieval, and modern history. Includes over 20,000 entries ranging from the prehistoric period to 2000.

A free, general subject encyclopedia on the web. InfoPlease's editors partner with Columbia University Press, TIME Magazine, and ESPN to provide reliable information. Some advertisements included.