Revision with unchanged content. Mobile applications running on personal devices, like smartphones, PDAs, or laptop computers, create a fascinating market for many new mobile services. Mobile commerce, location-based services, multimedia messaging, or mobile ga ming are expected to constitute a main driving-force for technological ad vance ments, creating a new source of revenue for infrastructure providers and developers. Based on what we observe today, the logical next steps lead to integrated infrastructures and applications supporting pervasive com pu ting . What ever this future will look like, the basic cornerstones will be: (i) highly no madic users, (ii) personalized devices running smart applications, (iii) per va sive smart infrastructures, and (iv) efficient communication for end-to-end in tegration of all building blocks. This book introduces the amazing world of pervasive computing, leads step-by-step through the new design challenges for pervasive computing appli ca tions and identifies the key challenges for engineering middleware supporting per vasive applications. Based on the well-known publish/subscribe paradigm it demonstrates how middleware systems can be designed to explicitly make use of context of users and applications. It then shows how context in for ma tion can be leveraged for optimizing the efficiency of communication in side a notification service.