daemon book

daemon book n.  "The Design and Implementation of the
   4.3BSD UNIX Operating System", by Samuel J. Leffler, Marshall Kirk
   McKusick, Michael J. Karels, and John S. Quarterman (Addison-Wesley
   Publishers, 1989, ISBN 0-201-06196-1) -- the standard reference
   book on the internals of {BSD} UNIX.  So called because the
   cover has a picture depicting a little devil (a visual play on
   {daemon}) in sneakers, holding a pitchfork (referring to one of
   the characteristic features of UNIX, the `fork(2)' system
   call).  Also known as the {Devil Book}.