Book excerpt: This book covers several aspects related the evolution of Information Systems into Pervasive Information Systems. New IT trends have an important impact on IT infrastructures, which become increasingly heterogeneous, flexible, and dynamic. These new trends are transforming Information Systems into what we call Pervasive Information Systems. The purpose of this book is to combine “state-of-the-art” solutions from various research communities (such as Information Systems Engineering, Cloud Computing, Fog/Edge Computing, Pervasive systems, Distributed systems, and Middleware systems) related to the Pervasive Information Systems emergence as a common point of view. Through these multiple contributions, this book tackles important challenges concerning Information Systems evolution, promoting a holistic view of Pervasive Information System. Pervasive Information Systems (PIS) can be defined as a new class of Information Systems. It can be characterized by an IT that is gradually embedded in the physical environment and can accommodate the user’s requirements and desires when necessary. This evolution implies considering Information Systems beyond the organization's physical environment to integrate new technologies transparently, leading to a pervasive environment whose behavior should be more and more reactive & proactive. It corresponds to an important change in Information Systems Engineering. Pervasive Information Systems are deeply multidisciplinary systems, demanding a holistic view in which multiple domains are invited to contribute.