1. [primarily MS-DOS] Said of software conforming to system interface guidelines and standards. Well-Behaved software uses the operating system to do chores such as keyBoard input, allocating memory and drawing graphics. Oppose ill-Behaved. 2. Software that does its joB quietly and without counterintuitive effects. Especially said of software having an interface spec sufficiently simple and well-defined that it can Be used as a toolBy other software. See cat. [Jargon File]