Donald B.Welbourn (1916- ) was educated at Emmanuel College, Cambridge (BA 1937), and became a University Lecturer in 1952. In 1971 he was appointed Director in Industrial Co-operation, and head of the Wolfson Cambridge Industrial Unit. He started the work on CADCAM in 1965. This led to the development of the DUCT system of CADCAM, and to the founding of Delcam International plc to develop it. Today it is the largest supplier of CADCAM for tooling world-wide, and the 5th largest supplier of CADCAM software overall. 35 years since the start of the work, the system has been redesigned by Delcam International plc to make use of modern computer technology, and is now known as the POWER family of CADCAM programs. Donald Welbourn is a Fellow of the Royal Academy of Engineering, a Corresponding Member of the Verein Deutscher Ingenieure, and a Fellow of Selwyn College.