onCue was an intelligent internet interface created by a dot-com startup, aQtive. onCue used data detectors to analyse clipboard content and proactively suggest useful web and desktop actions. It is an example of a context sensitive interface. The system was deliberately design using the principles of appropriate intelligence so that it was unobtrusive when its results were not needed.
Used in Chap. 19: page 308
Links:
alandix.com: 
onCue – designing appropriate interactions