This is the second book that appears as a product of the multi-disciplinary project Games, Action and Social Software'', which was carried out at the Netherlands Institute for Advanced Study in the Humanities and Social Sciences (NIAS) in Wassenaar, from September 2006 through January 2007. This project brought together a group of creative researchers from philosophy, logic, computer science, cognitive science and economics, to investigate the logical, computational and strategic aspects of social mechanisms. The aim was to arrive at a multi-disciplinary perspective, and help create an active community with a more definite agenda. One of the deliverables of the project was to be an overview of this emerging new field, including an agenda for further research, with the contents of the book to be shaped by discussions and interaction at NIAS. This promise was fulfilled with {\em Discourses on Social Software}, that appeared in 2009 with Amsterdam University Press in the series Texts in Logic and Games.