Joop van Oosterom (12 December 1937 – 22 October 2016) was a Dutch billionaire, chess and billiards sponsor, and twice correspondence chess world champion. He made his money with the Volmac Software Group. From 1992 to 2011 he staged the annual Melody Amber chess tournament in Monaco, where world-class Grandmasters played rapid and blindfold games. It is named after his first daughter Melody Amber. His other daughter was the eponym to the Crystal Kelly Cup, an invitational tournament for three-cushion carom billiards, which has been held between 1994 and 2011 mostly in Monte Carlo and Nice.