The application that actually makes a sustaining
market for a promising but under-utilized technology. First used
in the mid-1980s to describe Lotus 1-2-3 once it became evident
that demand for that product had been the major driver of the early
business market for IBM PCs. The term was then restrospectively
applied to VisiCalc, which had played a similar role in the success
of the Apple II. After 1994 it became commonplace to describe the
World Wide Web as the Internet's killer app. One of the standard
questions asked about each new personal-computer technology as it
emerges has become "what's the killer app?"