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

NPL
       Netscape Public License (Netscape)


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

NPL
       Non-Procedural Language


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

NPL

   1. New Programming Language.  IBM's original (temporary) name
   for PL/I, changed due to conflict with England's "National
   Physical Laboratory."  MPL and MPPL were considered before
   settling on PL/I.  Sammet 1969, p.542.

   2. A functional language with pattern matching designed by
   Rod Burstall and John Darlington in 1977.  The language
   allowed certain sets and logic constructs to appear on the
   right hand side of definitions, E.g.

   	setofeven(X) <= <:x: x in X & even(x) :>

   The NPL interpreter evaluates the list of generators from
   left to right so conditions can mention any bound variables
   that occur to their left.  These were known as set
   comprehensions.  NPL eventually evolved into Hope but lost
   set comprehensions which were called list comprehensions in
   later functional languages.

   [John Darlington, "Program Transformation and Synthesis:
   Present Capabilities", Research Report No. 77/43, Dept. of
   Computing and Control, Imperial College of Science and
   Technology, London September 1977.]

   3. NonProcedural Language.  A relational database language
   developed by T.D. Truitt et al in 1980 for Apple II and
   MS-DOS.

   ["An Introduction to Nonprocedural Languages Using NPL",
   T.D. Truitt et al, McGraw-Hill 1983].