Peter Norton (born November 14, 1943) is an American programmer, software publisher, author, and philanthropist. He is best known for the computer programs and books that bear his name and portrait. Norton sold his PC software business to Symantec Corporation in 1990. His earliest low-level system utilities were designed to allow mainframe programmers access to a block of RAM that IBM normally reserved for diagnostics. This foreshadowed his personal computer work, where he became known as a knowledgeable author of low-level system utilities and reference books.