WordNet (r) 3.0 (2006):

ABC
    n 1: the elementary stages of any subject (usually plural); "he
         mastered only the rudiments of geometry" [syn: rudiment,
         first rudiment, first principle, alphabet, ABC,
         ABC's, ABCs]

V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

ABC
       Atanasoff-Berry-Computer


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

ABC

   1.  Atanasoff-Berry Computer.

   2.  An imperative language and programming
   environment from CWI, Netherlands.  It is interactive,
   structured, high-level, and easy to learn and use.  It is a
   general-purpose language which you might use instead of
   BASIC, Pascal or AWK.  It is not a systems-programming
   language but is good for teaching or prototyping.

   ABC has only five data types that can easily be combined;
   strong typing, yet without declarations; data limited only
   by memory; refinements to support top-down programming;
   nesting by indentation.  Programs are typically around a
   quarter the size of the equivalent Pascal or C program,
   and more readable.

   ABC includes a programming environment with syntax-directed
   editing, suggestions, persistent variables and multiple
   workspaces and infinite precision arithmetic.

   An example function words to collect the set of all words in a
   document:

      HOW TO RETURN words document:
         PUT  IN collection
         FOR line in document:
            FOR word IN split line:
               IF word not.in collection:
                  INSERT word IN collection
         RETURN collection

   Interpreter/compiler, version 1.04.01, by Leo Geurts,
   Lambert Meertens, Steven Pemberton .
   ABC has been ported to Unix, MS-DOS, Atari, Macintosh.

   (http://cwi.nl/cwi/projects/abc.html).

   FTP eu.net (ftp://ftp.eu.net/programming/languages/abc),
   FTP nluug.nl (ftp://ftp.nluug.nl/programming/languages/abc),
   FTP uunet (ftp://ftp.uu.net/languages/abc).

   Mailing list: .

   E-mail: .

   ["The ABC Programmer's Handbook" by Leo Geurts, Lambert
   Meertens and Steven Pemberton, published by Prentice-Hall
   (ISBN 0-13-000027-2)].

   ["An Alternative Simple Language and Environment for PCs" by
   Steven Pemberton, IEEE Software, Vol. 4, No. 1, January 1987,
   pp. 56-64.]

   (1995-02-09)

   2.  Argument, Basic value, C?.

   An abstract machine for implementation of functional
   languages and its intermediate code.

   [P. Koopman, "Functional Programs as Executable
   Specifications", 1990].

   (1995-02-09)