The Apollo Guidance Computer (AGC) was the digital brain [ES1] for the Command and Lunar Modules. It controlled everything from guidance and navigation to input control. The source code was developed by a team at MIT led by Margaret Hamilton. Given that software engineering was a new field, Hamilton is quoted, “...there was no choice but to be pioneers.”

Here is a photo of her standing next to a printed copy of the source code for both the CM and LM.