Mersenne Wiki
- Information about the Great Internet Mersenne Prime Search, other distributed prime projects, and the related mathematics.
- http://mersennewiki.org

The Prime Pages: Mersenne Primes
- History, theorems, tables, conjectures, heuristics.
- http://primes.utm.edu/mersenne

Internet PrimeNet Server
- PrimeNet is a distributed computing project for the Great Internet Mersenne Prime Search, co-ordinating the assignment of work and collection of results.
- http://www.mersenne.org/ips/

mersenneforum.org
- A forum about prime numbers and computerized searches for more of them. Includes discussions of software and hardware issues encountered by searchers.
- http://www.mersenneforum.org/

Ars Technica Team Prime Rib
- A distributed computing team dedicated to finding Mersenne prime numbers.
- http://www.teamprimerib.com/

Marin Mersenne
- Biography of the Minim friar and his contributions to number theory. Includes references, pictures, and cross-references to topics.
- http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Mersenne.html

Mersenne Prime Digits and Names
- Landon Curt Noll lists the decimal, English, and American expansions of all the known Mersenne primes.
- http://www.isthe.com/chongo/tech/math/prime/mersenne.html

Will Edgington's Mersenne Page
- Files with Mersenne factors. Includes proofs of theorems related to the search for Mersenne primes and factors.
- http://www.garlic.com/~wedgingt/mersenne.html