Daniel Henry Holms Ingalls, Jr.

Inventor of BitBlit, the general-purpose graphical operation underlying most bitmap graphics systems, Ingalls is a pioneer of object-oriented computer programming and the principal architect, designer, and implementor of five generations of Smalltalk environments. He designed the bytecoded virtual machine that made Smalltalk practical in 1976. He also invented pop-up menus.

Ingalls designed the generalizations of BitBlt to arbitrary color depth, with built-in scaling, rotation, and anti-aliasing. His major contributions to the Squeak system included the original concept of a Smalltalk written in itself and made portable and efficient by a Smalltalk-to-C translator.