NASA Open Sources Apollo 11 Code (2009)
It's worth noting that the software, while only 36k machine words long, and the hardware, which was very slow even by the standards of other computers of the 60s, were remarkable works created in only a couple years by huge teams (peak of 800 people working on hardware and 400 on software IIRC).Its popular to dismiss the AGC as simple and uninteresting, but it was a challenging engineering task, and it never once had a failure in flight.There's lots of resources on the internet to read more. A great book on the topic is Digital Apollo by David Mindell