Dictionary of Computer and Internet Terms: killer app
killer app
(slang) a software application that becomes so desirable that it is the reason people purchase a computer, computer peripheral, or operating system. For example, Visicalc was a killer app for the Apple II, and Lotus 1-2-3 was a killer app for the original IBM PC. Some operating systems, such as OS/2, have failed to become popular because of the lack of a killer app.
