Charles "Charley" Muntz graduated from MIT with a degree in engineering in 1962. As a student he was chairman of the school newspaper, The Tech, and a member of the Phi Gamma Delta fraternity. Also as a student, he secured a summer job at the MIT Instrumentation Laboratory (IL) and was hired there full-time after he graduated. While at the IL Muntz worked in computer science and programming. He helped code early assembly programs as well as write the first Block I assembly program called SUNRISE. He wrote Interpreter, which was a list-processing interpretive language and an important part of the Apollo Guidance Computer software. It functioned as a set of subroutines that allowed for precise guidance and navigation calculations. Muntz also wrote the first Block II assembly program called RETREAD, and AURORA, the first assembler for the Lunar Module. Additionally, he helped develop the restart protection for the AGC which ensured the programs would still function if the computer briefly lost power or had to be restarted during a mission.
Muntz left the IL shortly before the first moon landing. He continued to work in computer engineering and software at Compass in Wakefield, MA where he eventually became company president and later Dartmouth Time Sharing System in Hanover, NH. He was married to Jill B. Muntz for 56 years and they had two sons.