The theme of the following work is the horizontalisation of productive human relationships that has been enabled through communication networks and in particular the Internet. These productive publics can generate their own practices and institutions through bottom-up dynamics, or they can be mobilized by existing institutions. Hence the emergence of the collaborative economy, which comes with many names and with different expressions, such as commons-based peer production (Yochai Benkler), wikinomics (Don Tapscott), crowdsourcing (Jeff Howe), open innovation (Henry Chesbrough), collaborative consumption (Rachel Botsman), and quite a few others. Different authors have mapped the outlines of those particular expressions of the collaborative economy, but we believe that an overall synthesis was still lacking. While a full account would be a tremendous undertaking, we do believe that the following work captures the essence of developments in this field, which represent a deep transformation of economic practices.