This program is used to find Mersenne Prime numbers

Prime95
Free
Offline
http://www.mersenne.org/primes/

Prime numbers have long fascinated amateur and professional mathematicians. An integer greater than one is called a prime number if its only divisors are one and itself. The first prime numbers are 2, 3, 5, 7, 11, etc. For example, the number 10 is not prime because it is divisible by 2 and 5. A Mersenne prime is a prime of the form 2P-1. The first Mersenne primes are 3, 7, 31, 127 (corresponding to P = 2, 3, 5, 7). There are only 44 known Mersenne primes.

It can also be listed under computer testing, because tt is often used to test computer cooling and stability.