A Hugo-winning science fiction novel by Vernor Vinge, about a quest to rescue two young children marooned on a medieval planet amid wolf-like gestalt creatures called Tines, and at the same time end the threat of an insane god/computer that threatens to ravage the entire galaxy if not stopped in time. Notable for featuring an analogue of the USENET on a galactic scale (and, if rumor is to be believed, imitations of the posting styles of various famous USENET kooks of the time it was written).

The prequel, A Deepness in the Sky, was published in 1999.

A Fire Upon the Deep is available for PDAs via Peanut Press.