According to Wikipedia, David G. Korn is an American UNIX programmer and the author of the Korn shell , a command line interface/programming language. Education and work David Korn received his undergraduate degree in mathematics from Rensselaer Polytechnic Institute in 1965 and his Ph.D. in applied mathematics from NYU's Courant Institute of Mathematical Sciences in 1969. After working on computer simulations of transsonic airfoils and developing the Korn airfoil, he switched fields to computer science and became a member of technical staff at Bell Laboratories in 1976. He developed Korn shell in response to problems he and his colleagues had with the most commonly used shells at the time, Bourne shell and C shell. The Korn shell pioneered the practice of consultative user interface design, with input from Unix shell users, and from mathematical and cognitive psychologists. The user interface, which included a choice of editing styles was incorporated into, or copied by, most subsequent Unix shells. The Korn shell is backward-compatible with Bourne shell, but takes a lot of ideas from C shell, such as history viewing and vi-like command line editing.