This is a contest started by mathgrant on his blog
here. It is an innovative contest where you can donate to 3 particular charities Grant has partnered with, and your donations will earn you a given number of entries into a prize raffle of the particular charity you choose. Grant has also mentioned he will upload huge puzzles each time the donation amount crosses a landmark.
The charities are -
1.
Sanctuary Home for Children
2.
Child's Play Charity
3.
Jack Vasel Memorial Fund