Millennium Prize Problems Save
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.
http://www.claymath.org/millennium/   

Mathematical Problems Save
In various subjects, compiled by Torsten Sillke.
http://www.mathematik.uni-bielefeld.d...   

Most Wanted List Save
Elementary unsolved problems in mathematics, listed at the MathPages archive.
http://mathpages.com/home/mwlist.htm   

Unsolved Mathematics Problems Save
Compiled by Steven Finch. Descriptions of some unsolved problems and numerous links to other collections.
http://www.mathsoft.com/mathsoft_reso...   

Unsolved Problem of the Week Archive Save
A list of unsolved problems published by MathPro Press during 1995.
http://cage.rug.ac.be/~hvernaev/probl...   

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