Lee mentioned the program in a speech he gave at a reception on April 20 before IT industry leaders. "The last program I wrote was a Sudoku solver in C++ several years ago, so I’m out of date," he said. "My children are in IT, two of them—both graduated from MIT. One of them browsed a book and said, 'Here, read this.'" It was a textbook on the Haskell programming language, Lee recounted. "One day that will be my retirement reading."