Source : Free On-Line Dictionary of Computing

well-behaved
     
        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 {tool} by other software.  See {cat}.
     
        [{Jargon File}]