This special issue draws together some of the contemporary research and development of ubiquitous computing, most of which was foretold by Licklider (1960) and Weiser (1991). Computers are ubiquitous--in terms that they are everywhere--but does this mean the same as ubiquitous computing? The convergent device view posits the computer as a tool through which anything and everything can be done. The divergent device view offers a world where microprocessors are embedded in everything and communicating with one another. This debate is implicitly present in this issue.
