A Pioneer is a person whose work founded, advanced or is closely identified with a field, language, concept or system this atlas records: a computer scientist, mathematician or engineer whose contribution is part of the historical record of computing. A Pioneer is not a Field, Language, Concept or System: the pioneer is the person, credited by name, with a birth year, nationality and the specific contribution the sources attribute to them, including honestly recorded priority disputes where the record shows more than one claimant.