tl;dr: Margaret Hamilton, the MIT computer scientist who led development of the Apollo program's onboard flight software and coined the term "software engineering," died September 30 at age 90. Her priority-driven software famously saved the Apollo 11 lunar landing when it handled a 1202 overload error, and she pioneered concepts like defensive programming and fault tolerance. After leaving MIT in the 1970s, she founded two software companies and received the Presidential Medal of Freedom in 2016.