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

demo version

   1. An early, barely-functional version of a program which
   can be used for demonstration purposes as long as the operator
   uses *exactly* the right commands and skirts its numerous
   bugs, deficiencies, and unimplemented portions.

   2. A special version of a finished program (frequently with
   some features crippled) which is distributed at little or no
   cost to the user for enticement purposes.  See crippleware.

   (1994-11-04)