The Jargon File (version 4.4.7, 29 Dec 2003):

cuspy
 /kuhs'pee/, adj.

    [WPI: from the DEC abbreviation CUSP, for ?Commonly Used System Program?,
    i.e., a utility program used by many people. Now rare.]

    1. (of a program) Well-written.

    2. Functionally excellent. A program that performs well and interfaces well
    to users is cuspy. Oppose rude.

    3. [NYU] Said of an attractive woman, especially one regarded as available.
    Implies a certain curvaceousness.


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

cuspy

   /kuhs'pee/ [WPI: from the DEC abbreviation CUSP, for
   "Commonly Used System Program", i.e. a utility program used by
   many people] 1. (of a program) Well-written.

   2. Functionally excellent.  A program that performs well and
   interfaces well to users is cuspy.  See rude.

   [Jargon File]