Introuction to Automata Theory, Languages, and Computation, also known as the Cinderella Book, is an influential computer science textbook by John Hopcroft and Jeffrey Ullman on formal languages and the theory of computation. The nickname is derived from a girl (putatively Cinderella) on the cover with a Rube Goldberg machine. The first edition was published in 1979, the second edition in November 2000, and third edition is February 2006. However, with the new edition, it includes some applications where automata theory is applied.