Literary Machines (short title) is a book first published in 1980 by Ted Nelson, and republished 9 times by 1993. It offers an extensive overview of Nelson's term "hypertext" as well as Nelson's Project Xanadu. It also includes other theories by Nelson, including "tumblers" for addressing bits in files past and present, "transclusion" as a method for including original work in one's own work, and "micropayments" to pay for the use. The format of the book is nonlinear, as the chapters are arranged in such a way that the text can be read out of order.