Solitaire, also known as Microsoft Solitaire, is a computer game included with Microsoft Windows, based on a card game of the same name, also known as Klondike. The game was initially developed in 1989 by then intern Wes Cherry, and the card decks were designed by Macintosh pioneer Susan Kare. Microsoft intended Solitaire "to soothe people intimidated by the operating system," and at a time where many users were still unfamiliar with graphical user interfaces, it proved useful in familiarizing them with the use of a mouse, such as the drag-and-drop technique required for moving cards.
"A few people have paid me 'a penny' as a joke. I'd get them in the mail, or in person if someone introduced me as the author of Solitaire and the obligatory no royalties conversation came up. I think I'm up to about 8 cents now."