Book excerpt: Welcome to the proceedings of the 2005 IFIP International Conference on - bedded and Ubiquitous Computing (EUC 2005), which was held in Nagasaki, Japan, December 6–9, 2005. Embedded and ubiquitous computing is emerging rapidly as an exciting new paradigm to provide computing and communication services all the time, - erywhere. Its systems are now pervading every aspect of life to the point that they are hidden inside various appliances or can be worn unobtrusively as part of clothing and jewelry. This emergence is a natural outcome of research and technological advances in embedded systems, pervasive computing and c- munications, wireless networks, mobile computing, distributed computing and agent technologies, etc. Its tremendous impact on academics, industry, gove- ment, and daily life can be compared to that of electric motors over the past century, in fact it but promises to revolutionize life much more profoundly than elevators, electric motors or even personal computers. The EUC 2005 conference provided a forum for engineers and scientists in academia, industry, and government to address profound issues including te- nical challenges, safety, and social, legal, political, and economic issues, and to present and discuss their ideas, results, work in progress, and experience on all aspects of embedded and ubiquitous computing.