Rand and Robyn Miller, brothers, the first a programmer and the second a visual artist, published the children's computer exploration-game Manhole in 1988, which was followed by Cosmic Osmo in 1989 and then by Myst — a ‘game’ for adults — in 1994. (All these games are published on CD-ROM, and have been followed by “Riven” in 1997.) In an article about the success of Myst, Jon Carroll has described the game as “a puzzle box inside a novel inside a painting only with music. Or something.” Myst was designed so that most players would need to spend approximately 40 hours to solve the central puzzle, a puzzle whose pieces are linked by — and centered in — the pages of books.