Recording the first ten years' progress on the computerized aspects of the DMLCS project, this volume also constitutes a wide-ranging survey of such lexicographical enterprises as the field developed in the third quarter of the twentieth century. Particular attention is devoted to common methodological problems and the various solutions that were attempted. The book is an ancillary volume to the Royal Irish Academy's "Dictionary of Medieval Latin from Celtic Sources" project, whose main publications are detailed at http://journals.eecs.qub.ac.uk/DMLCS.