I'd like to discuss another issue: using a persistent data structure for the buffer so that some functionality can be obtained for free, such as - unlimited undo - storing the editing history together with the latest version of a file (could be used for better computing of version differences than with cvs-diff) I am still looking for appropriate data structures. A good, brief intro into this area is http://ocw.mit.edu/NR/rdonlyres/Electrical-Engineering-and-Computer-Science/... (See Section 5.2.3.) Is anyone else interested in pursuing this? Any other ideas? Alex __________________________________ Do you Yahoo!? New and Improved Yahoo! Mail - Send 10MB messages! http://promotions.yahoo.com/new_mail