The Free On-line Dictionary of Computing (30 December 2018):

Green Book

   1.   Informal name for one of the four standard
   references on PostScript.  The other three official guides
   are known as the Blue Book, the Red Book, and the White
   Book.

   ["PostScript Language Program Design", Adobe Systems,
   Addison-Wesley, 1988 (ISBN 0-201-14396-8)].

   2.  Informal name for one of the three standard
   references on SmallTalk.  Also associated with blue and red
   books.

   ["Smalltalk-80: Bits of History, Words of Advice", by Glenn
   Krasner (Addison-Wesley, 1983; QA76.8.S635S58; ISBN
   0-201-11669-3)].

   3.   The "X/Open Compatibility Guide", which
   defines an international standard Unix environment that is a
   proper superset of POSIX/SVID.  It also includes
   descriptions of a standard utility toolkit, systems
   administrations features, and the like.  This grimoire is
   taken with particular seriousness in Europe.  See Purple
   Book.

   4.   The IEEE 1003.1 POSIX Operating Systems
   Interface standard has been dubbed "The Ugly Green Book".

   5.   Any of the 1992 standards issued by the
   ITU-T's tenth plenary assembly.  These include, among other
   things, the dreadful X.400 electronic mail standard and
   the Group 1 through 4 fax standards.

   6. Green Book CD-ROM.

   See also book titles.

   [Jargon File]

   (1996-12-03)