Library: Math
The MacTutor History of Mathematics Archives
Brief articles on topics in the history of mathematics, information on Greek mathematics, and biographical information about mathematicians.
MathWorld
A comprehensive and interactive mathematics encyclopedia created by Eric Weisstein.
The Math Forum: Ask Dr. Math
Frequently asked questions about elementary to college-level math.
Unsolved Problems
A collection of unsolved mathematics problems and partial answers.
Women in Mathematics
Biographies of women in mathematics, created as part of an ongoing project by mathematics students at Agnes Scott College in Atlanta, Georgia.