Octavo provides a modification of the standard LaTeX book class to typeset books following classical layout and design principles. In particular, book formats are set to classical sizes such as foolscap, crown, post, demy, etc., margins are set harmonically, an attempt is made to maintain a constant grid of printed lines throughout the text, and the page styles are defined more discretely. The documentation includes methods to produce signatures so that books can actually be made by the user. The author is S Revets.