Idea shared between 1993 and 1996 between researchers from EPFL and other universities in Argentina, Bolivia, Brasil and Venezuela, with the support of the Foundation Leopold Mayer for the Progress of Man, alternative ways of urban planning have been tested in several cities of these countries, involving representatives of different institutions and social groups in a participatory form. The book makes a synthesis of actions done in each countries and offers a globa thinking about what is the aim of planning.