PrimeGrid is a distributed computing project for searching for prime numbers of world-record size. It makes use of the Berkeley Open Infrastructure for Network Computing (BOINC) platform. As of August 2010, there are about 5,000 active participants (on about 11,500 host computers) from 89 countries, reporting about 65 teraflops.
- 321 Prime Search searching for mega primes of the form 3×2n±1.
- AP27 Search: searching for an arithmetic progression (p+dn) that yields primes for 27 consecutive values of n.
- Cullen numbers / Woodall numbers Search: searching for mega primes of forms n×2n±1
- Extended Sierpiński problem: helping solve the Extended Sierpinski Problem.
- Generalized Cullen/Woodall Prime Search: searching for primes of the form n×bn±1.
- Generalized Fermat number Search: searching for megaprimes of the form b2n+1.
- Prime Sierpinski project: helping Prime Sierpiński Project solve the Sierpiński problem.
- Proth prime Search: searching for primes of the form k×2n+1.
- Seventeen or Bust: helping to solve the Sierpiński problem.
- Sierpinski-Riesel Base 5: helping to solve the Sierpiński-Riesel Base 5 Problem.
- Sophie Germain prime Search: searching for primes p and 2p+1.
- The Riesel problem: helping to solve the Riesel problem.