This book introduces the inter-organizational information systems to manage the activities of inter-organizational virtual organizations, extended enterprise, and trans-enterprise systems. The main focus of this book is to introduce basic concepts and technologies from IOIS, review and analysis of empirical research on adoption and diffusion IOIS, a new method to study IOIS, provide empirical evidence on how information systems encourage the creation of strategic networks, inter-organizational information systems to share / decision support systems, and evaluation IOIS.