---
title: Grace Hopper
tags: [biography, compilers, cobol, navy]
status: active
confidence: high
created: 2026-04-09
sources:
  - file: public-domain/hopper-biography-usn.txt
    hash: placeholder
    size: 0
    ingested: 2026-04-09
aliases: []
---

# Grace Hopper

Grace Brewster Murray Hopper (1906–1992) was an American computer scientist and United States Navy rear admiral. She pioneered the idea that programs could be written in human-readable language and automatically translated to machine instructions — an idea her contemporaries dismissed as impossible.

## The First Compiler

In 1952, Hopper created the A-0 System, widely regarded as the first compiler. She demonstrated that a program could translate symbolic mathematical code into machine language, collapsing a manual translation process that previously took programmers days into seconds. The insight was philosophical as much as technical: she insisted that computers should adapt to humans, not the other way around.

## COBOL

Hopper was the primary force behind COBOL (Common Business-Oriented Language), standardised in 1960. She championed the use of English-like syntax for business data processing, making computing accessible to non-mathematicians. COBOL ran the world's financial infrastructure for decades and still processes an estimated $3 trillion in daily commerce. See [[programming-languages-overview]] for context on how COBOL fits into language history.

## Naval Career and Debugging

Hopper served in the Navy for 43 years, retiring at 79 as the oldest active-duty officer in the U.S. military. She popularised the term "debugging" after her team found a literal moth causing a relay failure in the Harvard Mark II computer in 1947 — they taped it into the logbook with the note "first actual case of bug being found."

## Legacy

Hopper's work established that [[von-neumann-architecture]] hardware could be programmed productively through high-level languages, not just assembly. The annual Grace Hopper Celebration of Women in Computing, the largest gathering of women technologists, is named in her honour.

See also: [[alan-turing]] for the theoretical foundations she built upon; [[programming-languages-overview]] for the languages her compiler work made possible.
