David John Wheeler (1927- 2004) was involved with some of the earliest computers. He was a pioneer of the EDSAC computer at Cambridge and he helped to develop assembly language. Long before there was object-oriented programming, David Wheeler created the closed subroutine, which enabled segments of code to be written independently of the main application flow and called as needed. He is particularly remembered for his work on data compression. He was a private man who was not well known outside the academic computer science community, but his significant contribution to modern computing was widely acknowledged within the field.