This book argues that many positive planning and policy outcomes can result when GIS experts and community organizers work together to address problems affecting our neighborhoods and cities. This book is written by an author who, in addition to being an academic, has worked for twenty years in the grassroots, designing and implementing a wide range of community-oriented GIS activities. The book is both an account of personal experiences, as well as an academic reflection of professional practice. The case studies are drawn from multiple scales and represent stake holders covering a wide swath of actors. For practitioners, the book will help to place their own experiences into a historical and socio-political context and will provide guidance for their work. For students, it looks behind the scenes of glossy PPGIS reports usually found in the literature. For policymakers, it highlights the pathways to facilitate social change through consensus building. This book provides clarity about terminologies and definitions. It provides practical guidelines for policymakers seeking to implement consensus-building approaches that are supported by GIS and other digital tools.