Warren Teitelman (February 21, 1941 – August 12, 2013)[4][5] was an American computer scientist known for his work on programming environments and the invention and first implementation of concepts including Undo / Redo,[6] spelling correction, advising, online help, and DWIM (Do What I Mean).
Warren Teitelman presented a novel scheme for real time character recognition in his master's thesis submitted in 1966 at MIT.
[14] He developed a program on the SDS 940 for Bob Kahn that allowed experimentation with various routing policies in order to see the effect on network traffic and real time monitoring of the packets.
[17] In Interlisp, Teitelman invented DWIM ("Do What I Mean"), a function that attempted to correct many common typing errors.
[18] The program was developed based upon Teitelman's own writing style and idiosyncrasies in 1972, and then used by other individuals in his office, followed by users across the industry.
D-Lisp used the Alto as a display device on which ran the window manager and event handler, communicating with Interlisp running on a MAXC (a PDP-10 clone).