Penman is the result of work by many people. Important contributions were made by Drs. Christian Matthiessen and William Mann (the two principal architects of the system), Drs. John Bateman, Robert Kasper, Cécile Paris, Peter Fries, Michael Halliday, Norman Sondheimer, Susanna Cumming, Cecilia Ford, William Swartout, Ms. Lynn Poulton, Messrs. Robert Albano and Mick O'Donnell, and by the current Penman staff. In addition, for many years the Penman project has benefitted from the work of visitors too numerous to list.