He designed the generalizations of BitBlt to arbitrary color depth, with built-in scaling, rotation, and anti-aliasing.

While working toward a Doctor of Philosophy (Ph.D.) at Stanford, he started a company to sell a software measurement invention that he perfected, and never returned to academia.

As Peter Siebel wrote about Dan in his book Coders at Work, Reflections on the Craft of Programming, "If Alan Kay is Smalltalk's father, Dan Ingalls is its mother—Smalltalk may have started as a gleam in Alan Kay's eye, but Ingalls is the one who did the hard work of bringing it into the world.

Publication date: June 2020, which details the design of Smalltalk through Ingalls's multiple iterations of the language, including his development of Squeak in 1996.

[8] Larry Tesler mentioned to Alan Kay and Dan Ingalls that he thought blocks of bits could be easily moved on the screen.

Diana Merry had been working on programming text display, and after talking to her, Ingalls dug into the problem.

Called Bit Blit, it enabled graphical menu systems to "pop-up" instantly on an Alto screen in response to a mouse click.

He left research in 1987, for a time to run the family business, the Homestead Resort,[10] in Hot Springs, Virginia.

He was a key member of the chief scientist team guiding the company's technology vision, direction, and execution.

[18] In 1984, Ingalls received the Association for Computing Machinery (ACM) Grace Murray Hopper Award for Outstanding Young Scientist, for his Xerox PARC research, including bit blit.