The visionary life of a Belgian utopian, Paul Otlet (1868-1944) who cultivated a strange sort of obsession: to classify, encode and unify all kinds of books and documents published in the world. Over the years, he and his staf would fill in 12 millions index cards. His classification system is regarded today as similar to the hypertext that enables us to navigate through the computer network. Few people today know the name of Paul Otlet, nor the terms Mundaneum or World City. At times tinted with grandeur, at others with pathos, the Mundaneum project is as related to the history of the book and libraries as it is to international institutions and the pacifist movement. Through the role that Le Corbusier played, it also constitutes an important chapter in modern urbanization. But the Mundaneum appears to be, through certain intuitions of Paul Otlet, the precursor of the Internet and the global information society that we live in today.