This volume provides an overview and an understanding of REST (Representational State Transfer). Discussing the constraints of REST the book focuses on REST as a type of web architectural style. The focus is on applying REST beyond Web applications (i.e., in enterprise environments), and in reusing established and well-understood design patterns when doing so. The reader will be able to understand how RESTful systems can be designed and deployed, and what the results are in terms of benefits and challenges encountered in the process. Since REST is relatively new as an approach for designing Web Services, the more advanced part of the book collects a number of challenges to some of the assumptions and constraints of REST, and looks at current research work on how REST can be extended and applied to scenarios that often are considered not to be a good match for REST. This work will help readers to reach a deeper understanding of REST on a practical as well as on an advanced level.