Résumé : During the past few years, Human Cities as a project and as a network, has aspired to come to terms with the gap between the practice and the theory of urban issues. This online publication is no exception; it is rooted in actions initiated by civil society to reclaim public space. It continues its way along academic and professional thoughts about this phenomenon and we hope it will enlighten and empower all kinds of people working with public spaces. It is an attempt to describe, analyse, evaluate and disseminate initiatives started by citizens, in order to foster imagination, creativity, collective experiments and criticism in contemporary cities. Indeed, as the pragmatist philosopher John Dewey put it, we strongly believe that researchers “must accept reality as they found it and try to shape it toward positive social goals, not stand aside in self-righteous isolation.” This publication shows many aspects and viewpoints of public spaces. It allows different profiles to meet in the same book and by this expands the field of discussion, as well as refines the attitudes towards the subject.