She invented the first compiler, which is a program that translates a computer language like Java or C++ into machine code, called assembly, that can be read by a processor. Every single program you use, every OS and server, was made possible by her first compiler.
SEE ALSO: Employee of the Century
A pioneer in the field, she was one of the first programmers of the Harvard Mark I computer, and developed the first compiler for a computer programming language. She conceptualized the idea of machine-independent programming languages, which led to the development of COBOL, one of the first modern programming languages. She is credited with popularizing the term "debugging" for fixing computer glitches (motivated by an actual moth removed from the computer).
What's cooler? She was a United States Navy Rear Admiral. In fact, the U.S. Navy destroyer USS Hopper (DDG-70) is named for her, as was the Cray XE6 "Hopper" supercomputer at NERSC. Owing to the breadth of her accomplishments and her naval rank, she is sometimes referred to as "Amazing Grace"