/grēn bu̇k/
n. 1. One of the three standard PostScript references: 'PostScript Language Program Design', bylined 'Adobe Systems' (Addison-Wesley, 1988; QA76.73.P67P66 ISBN; 0-201-14396-8); see also Red Book, Blue Book).
2. Informal name for one of the three standard references on SmallTalk: 'Smalltalk-80: Bits of History, Words of Advice', by Glenn Krasner (Addison-Wesley, 1983; QA76.8.S635S58; ISBN 0-201-11669-3) (this, too, is associated with blue and red books).