This book presents a state-of-the-art view of antimatter-matter chemistry and physics, with emphasis on the nanoscopic interactions of positronium atoms with ordinary matter. Selected applications are also discussed. The chapters present a summary of current knowledge in terms of both theory and experiment and as look to the future of research in this area. Extensive bibliographies are included to make the volume a useful reference book. This volume is intended for a broad audience, ranging from specialists in postron research to the graduate students who could use one or a few of the chapters as the introduction to a research area.