Sudoku becomes popular

In 1997, Wayne Gould, a man from New Zealand, was visiting Tokyo. While he was browsing a bookstore, he saw the squares and felt tempted to fill them in. Over the next six years, he developed a computer program that instantly makes up Sudoku puzzles.

Gould's wife published one of his puzzles in the local newspaper. It spread to Britain and was published in the Times, where it took off.