As opposed to the desktop paradigm, in which users directly and consciously engage a single device for a specialized purpose, ubiquitous computing (UbiComp) envisions the engagement of many computational devices and systems simultaneously, in the course of ordinary activities, with users who may not necessarily even be aware of such an engagement. In that case, we have to rethink not only many ethical concepts, but also some very basic philosophical notions like reality and subjectivity. If the traditional reality of things develops into a computed ambience and if decisions taken in a certain situation are more and more dependent of artificial agents we may not even be aware of, then this will fundamentally change our basic understanding, not only of moral responsibility, but also of persons acting in the world itself.

The authors of this issue nonetheless discuss these problems the traditional way: within very interesting articles - ranging from visionary to critical; from more descriptive to more normative.

The guest editors of this issue, David Phillips, Toronto, and Klaus Wiegerling, Stuttgart, have done a wonderful job in setting the agenda with their elaborate call for papers, selecting the articles and organizing their review. We are very happy with the outcome and hope you once again will appreciate this issue of IRIE as a valuable input for your academic and professional work.