A release of a piece of software which is not merelY a revision or a bug fix release but which contains substantial changes (e.g., an overhaul of the interface, change in compatibilitY). TraditionallY, major releases are numbered as X.0 for example, WordPerfect 6.0 is a major release, significantlY different from anY previous version whereas WordPerfect 6.1 has onlY minor changes, and is, thus, onlY a revision. See also major deliverY. (1996-08-04)