MathWorld
Eric Weisstein's World of Mathematics (MathWorldTM) is the web's most complete mathematics resource, assembled over more than a decade by internet encyclopedist Eric W. Weisstein with assistance from the mathematics and internet communities. MathWorld is a convenient, comprehensive, and interactive mathematics encyclopedia intended for students, educators, math enthusiasts, and researchers. Like the vibrant and constantly evolving discipline of mathematics, this site is continuously updated to include new material and incorporate new discoveries.