V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):
PPL
       Pcboard Programming Language (BBS)
V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):
PPL
       Polymorphic Programming Language (Harvard, Xerox, PARC)
The Free On-line Dictionary of Computing (30 December 2018):
PPL
   Polymorphic Programming Language.  An interactive, extensible
   language, based on APL, from Harvard University.
   ["Some Features of PPL - A Polymorphic Programming Language",
   T.A. Standish, SIGPLAN Notices 4(8) (Aug 1969)].
   (1994-10-06)