and have even achieved a degree of official recognition, the integration of new technologies into the mathematical practice of schools remains marginal. It is this situation which has motivated the research and development work to be reported in this volume. The appearance of ever more powerful and portable computational tools has certainly given rise to continuing research and development activity at all levels of mathematical education. Amongst pioneers, such innovation has often been seen as an opportunity to renew the teaching and learning of mathematics. Equally, however, the institutionalization of computational tools within educational practice has proceeded at a strikingly slow pace over many years.