Computers are widely recognised as powerful tools in many aspects of contemporary society. Significantly their agency is now changing as the social and spatial disposition of computers diffuses further into almost all aspects of everyday life. Computers, that increasingly don’t look like computers, are permeating domestic spaces, built into appliances like washing machines for example, and accompany us throughout the day (energising our mobile phones, PDAs and MP3 players), mediating our interactions and facilitating a myriad of mundane activities. Many argue that this is just the beginning of the next wave of digital technological development, the so-called pervasive computing revolution, which according to Anne Galloway (2004, pages 384-5), “seeks to embed computers into our everyday lives in such ways as to render them invisible and allow them to be taken for granted.” Such computing, that is active-in-absence heralds much more subtle forms of software mediation and automated decision-making in the world. It is this code work that is the focus of this theme issue1.