Introduction

Abstract

At the time of this writing, we are facing a world with a huge, and ever increasing number of real-world objects with embedded computing and communication capabilities. This development is mainly driven by technological advances within the past few decades, which have made it possible to shrink sensors and actuators as well as processing and wireless communication technologies to a size that enables their integration into virtually everything. Things of everyday use in industrial settings, in manufacturing, in offices or in homes, like tools, appliances, machinery, furniture or even clothing have become the constituent “devices”, through which applications interact with the user, and there is strong evidence that this trend will continue. It can be observed that the “computer” is no longer a single desktop device, but is rather associated with services originating in the “digital world” and perceived through the “physical world”. The computer is more and more hidden in the fabric of everyday life, invisibly networked, and accessible everywhere; thus, we could say that computers become invisible, while their interfaces become omnipresent.