- A software application that is particularly useful.
- A technology so compelling that it drives the sales of, or leads to widespread adoption of, related technologies.
- "Said Julian Horwich, executive director of the Chicago Association of Microcomputer Professionals: 'Everybody has only one killer application. The secretary has a word processor. The manager has a spreadsheet."
Ken Siegmann, "Developers remain optimistic despite sluggish growth of integrated programs," PC Week
- "The original killer app was considered to be Lotus 1-2-3, because it made the IBM-compatible personal computer a must-have item in business.
Most recently, the World Wide Web has been called the killer app for the Internet, making it essential. And the Internet itself has been called a killer app, validating the concept of computer networks."
" 'Killer app' apt to be nothing really special," The Houston Chronicle