This book is the first attempt to bring together current research findings in the domain of interactive horizontal displays. The novel compilation will integrate and summarise findings from the most important international tabletop research teams. It will provide a state-of-the art overview of this research domain and therefore allow for discussion of emerging and future directions in research and technology of interactive horizontal displays.Latest advances in interaction and software technologies and their increasing availability beyond research labs, refuels the interest in interactive horizontal displays. In the early 1990s Mark Weisers vision of Ubiquitous Computing redefined the notion of Human Computer Interaction. Interaction was no longer considered to happen only with standard desktop computers but also with elements of their environment.This book is structured in three major areas: under, on/above and around tabletops. These areas are associated with different research disciplines such as Hardware/Software and Computer Science, Human Computer Interaction (HCI) and Computer Supported Collaborative Work (CSCW). However, the comprehensive and compelling presentation of the topic of the book results from its interdisciplinary character. The book addresses fellow researchers who are interested in this domain and practitioners considering interactive tabletops in real-world projects. It will also be a useful introduction into tabletop research that can be used for the academic curriculum.