Mathematical Problems
In various subjects, compiled by Torsten Sillke.
Millennium Prize Problems
The seven problems proposed by the Clay Mathematics Institute: P versus NP; Hodge Conjecture; Poincaré Conjecture; Riemann Hypothesis; Yang-Mills Existence and Mass Gap; Navier-Stokes Existence and Smoothness; Birch and Swinnerton-Dyer Conjecture. Resources include articles on each problem by leading researchers.
Most Wanted List
Elementary unsolved problems in mathematics, listed at the MathPages archive.
Some Unsolved Problems with Elementary Formulation
Statements of some famous problems compiled by Frank Wikstrom, Ume? University.
Unsolved Mathematics Problems
Compiled by Steven Finch. Descriptions of some unsolved problems and numerous links to other collections.
Unsolved Problem of the Week Archive
A list of unsolved problems published by MathPro Press during 1995.