This study took place in a climate of an intensified focus on approaches to whole school improvement through 'embedding' technology in teaching, learning and management. It examined the evolution over time of classroom practice supported by information and communication technology (ICT) and its wider implementation within and outside of subject departments. Three years earlier a group of teachers in five secondary schools in England had participated in a collaborative programme of ten small-scale research projects in which they developed a range of pedagogical strategies involving use of ICT. These spanned six main Curriculum areas: English, classics, geography, history, science and technology, plus a language support group. The present study investigated the extent of development and dissemination of these practices over time, and identified the underlying mechanisms and supportive or constraining factors. This follow-up study comprised an interview survey of the 16 teachers and nine of their colleagues. Pedagogical approaches to using new technologies proved to be robust over time, to be spreading from subject teachers to their colleagues, and to be integrated into departmental schemes of work. However, findings indicated that evolution of practice depends on adequate access to reliable resources, and development of ICT as a school priority in turn leads to soliciting further resources and expanding practice. Individual teachers' confidence, skills and motivation towards using ICT to promote learning develop in response to other contextual factors, most prominently a supportive organizational culture and a collegial environment, and they play a critical role in the processes of developing and disseminating new practice. These processes are thus complex and iterative.