On October 13, 1969, MIT's Charles Stark Draper Laboratory published the technical report documenting the software systems used in the Apollo 11 guidance computer. The primary author of the onboard software was Margaret Hamilton.

Hamilton was born in 1936 in Paoli, Indiana. She studied mathematics at Earlham College and arrived at MIT in 1960 intending to pursue a doctorate in abstract mathematics. She took a temporary programming position to fund the degree and never left. She became director of Software Engineering at the MIT Instrumentation Laboratory, where she led the team that developed the flight software for the Apollo missions.

She coined the term "software engineering" — because she believed software deserved the same rigor and discipline as hardware engineering, a position the computing establishment resisted, insisting that programming was not engineering. The term eventually displaced the resistance.

The Apollo software she oversaw was novel in every respect: there were no predecessors, no established practices, no field to draw on. Her team developed asynchronous software, priority scheduling, and end-to-end testing as they went. During the Apollo 11 descent to the lunar surface, the guidance computer issued a series of 1202 program alarms — executive overflows caused by the landing radar being accidentally left on. The computer, following priority interrupt protocols Hamilton's team had built in precisely for this kind of overload situation, began shedding lower-priority tasks and completing the descent. The astronauts landed.

She received the Presidential Medal of Freedom in 2016.