It was discovered by the CMSU team of Dr. Curtis Cooper and Dr. Steven Boone on September 4, 2006, with a total of 9808358 digits.
This project has achieved great success: as of February 29, 2012, GIMPS has searched 13 Mersenne primes, each of which is the largest known prime number at that time. The largest known prime number was discovered on August 23, 2008, with a total of 12978189 digits.
In terms of license treaty, GIMPS software is not free software, it is only open source software, because it has restrictions that free software cannot accept - users must receive bonus distribution terms.