The Jargon File (version 4.4.7, 29 Dec 2003):
insanely great
 adj.
    [Mac community, from Steve Jobs; also BSD Unix people via Bill Joy]
    Something so incredibly elegant that it is imaginable only to someone
    possessing the most puissant of hacker-natures.
The Free On-line Dictionary of Computing (30 December 2018):
insanely great
   (Macintosh community, from Steve Jobs; also BSD Unix
   people via Bill Joy) Something so incredibly elegant that
   it is imaginable only to someone possessing the most puissant
   of hacker-natures.
   [Jargon File]
   (1994-12-06)