The study of manuscripts is one of the most active areas of current research in medieval studies: manuscripts are the basic primary material evidence for literary scholars, historians and art-historians alike, and there has been an explosion of interest over the past twenty years. Manuscript study has developed enormously: codices are no longer treated as inert witnesses to a culture whose character has already been determined by the modern scholar, but are active participants in a process of exploration and discovery. The articles collected here discuss the future of this process and vital questions about manuscript study for tomorrow's explorers. They deal with codicology and book production, with textual criticism, with the material structure of the medieval book, with the relation of manuscripts to literary culture, to social history and to the medieval theatre, and with the importance to manuscript study of the emerging technology of computerised digitisation and hypertext display. The essays provide an end-of-millennium perspective on the most vigorous developments in a rapidly expanding field of study. DEREK PEARSALL is former Professor and Co-Director of the Centre for Medieval Studies, York, and Professor of English at Harvard University.