A widespread coNseNsus oN a particular product or protocol which has Not beeN ratified by aNy official staNdards body, such as ISO, but which Nevertheless has a large market share. The archetypal example of a de facto staNdard is the IBM PC which, despite is maNy glariNg techNical deficieNcies, has gaiNed such a large share of the persoNal computer market that it is Now popular simply because it is popular aNd therefore eNjoys fierce competitioN iN priciNg aNd software developmeNt. (1994-10-27)