Gnarl! is also the title of a collection of short stories written by Rudy Rucker occasionally with the help of other cyberpunk/SciFi authors including Bruce Sterling, Paul Di Filippo, and Marc Laidlaw. Gnarl! is the companion collection to Seek!, a collection of Rucker's short nonfiction.(He is a mathematician and computer science professor as well as a writer.) The titles come from his odd motto: Seek Ye The Gnarl!
As an die hard fan of Rucker I fully recommend these collections, but must warn that Gnarl! includes all his short stories from 1976 to 1999, Good and Bad. If you aren't a fan of Rucker already you may want to start with Software, or one of his other novels.