Announcement of Completion – The Flyspeck Project

They have produced a formal proof of the Kepler Conjecture [1].

A non-formal proof had been produced by Thomas Hales, but mathematicians were not able to verify that it was correct. A panel of 12 referees spent 4 years reviewing Hales proof and were "99% certain" it was correct. Hales started the Flyspeck Project to produce a formal proof to settle the matter.

[1] http://en.wikipedia.org/wiki/Kepler_conjecture