Naval officer and computer scientist developed the first working compiler and led the effort in the 1960s to develop COBOL (Common Business-Oriented Language) a programming language still in use. When Hopper first came to the bureau of ordnance she met the mark 1 computer. She became the third person to program the mark 1 become. After a week she knew everything there was about the mark 1 . Which she later started the development of the the mark 2.