GIMPS Milestones

December 31, 2007: All exponents below 20,000,000 tested at least once.
December 3, 2007: All exponents below 16,000,000 double-checked.
September 4, 2006: Prime M(32582657) discovered!!
July 10, 2006: Double-checking proves M(13466917) is the 39th Mersenne prime.
December 15, 2005: Prime M(30402457) discovered!
February 18, 2005: Prime M(25964951) discovered!
May 15, 2004: Prime M(24036583) discovered!
November 17, 2003: Prime M(20996011) is discovered!
February 2, 2003: Double-checking proves M(6972593) is the 38th Mersenne prime.
November 14, 2001: Prime M(13466917) is discovered!
May 19, 2000: Double-checking proves M(2976221) and M(3021377) are the 36th and 37th Mersenne primes.
June 1, 1999: Prime M(6972593) is discovered!
December 18, 1998: Double-checking proves M(1398269) is the 35th Mersenne prime.
March 29, 1998: Double-checking proves M(1257787) is the 34th Mersenne prime.
January 27, 1998: Prime M(3021377) is discovered!
August 30, 1997: Double-checking proves M(756839) and M(859433) are the 32nd and 33rd Mersenne primes.
August 24, 1997: Prime M(2976221) is discovered!
November 13, 1996: Prime M(1398269) is discovered!
Third quarter, 1996: Double-checking proves M(216091) is the 31st Mersenne prime.

Some older and less important GIMPS Milestones

April 23, 2007: All exponents below 15,000,000 double-checked.
September 11, 2006: All exponents below 14,000,000 double-checked.
June 13, 2006: All exponents below 13,000,000 double-checked.
March 1, 2006: All exponents below 17,000,000 tested at least once.
December 24, 2005: All exponents below 16,000,000 tested at least once.
April 26, 2005: All exponents below 10,000,000 double-checked.
February 23, 2005: All exponents below 15,000,000 tested at least once.
October 3, 2004: All exponents below M(13466917) tested at least once.
September 17, 2004: All exponents below 9,000,000 double-checked.
March 9, 2004: All exponents below 12,000,000 tested at least once.
February 23, 2004: All exponents below 8,000,000 double-checked.
December 16, 2002: All exponents less than 6,000,000 double-checked.
July 19, 2002: All exponents below 10,000,000 tested at least once.
May 2, 2002: All exponents less than 5,000,000 double-checked.
April 15, 2002: All exponents below 9,000,000 tested at least once.
September 25, 2001: All exponents below 8,000,000 tested at least once.
July 25, 2001: All exponents below M(6972593) tested at least once.
May 20, 2001: All exponents less than 4,000,000 double-checked.
April 6, 2001: First 10 million digit number sucessfully double-checked.
April 1, 2001: All exponents less than 6,000,000 tested at least once.
September 25, 2000: First 10 million digit number tested for primality.
March 15, 2000: All exponents less than 5,000,000 tested at least once.
October 16, 1999: All exponents less than 2,000,000 double-checked.
August 19, 1999: All exponents less than 4,000,000 tested at least once.
December 26, 1998: All Mersenne numbers less than a million digits tested at least once.
September 26, 1998: All exponents below M(3021377) tested at least once.
September 19, 1998: All exponents below M(2976221) tested at least once.
March 5, 1998: All exponents below 2,000,000 tested at least once.
October 30, 1997: All exponents below 1,000,000 double-checked.
October 11, 1997: All exponents below M(1398269) tested at least once.
August 28, 1997: All exponents below M(1257787) tested at least once.
May 26, 1997: All exponents below 1,000,000 tested at least once.
March 28, 1997: All exponents below M(859433) tested at least once.
January 15, 1997: All exponents below M(756839) tested at least once.