The Free On-line Dictionary of Computing (30 December 2018):
Portable Forth Environment
    (PFE) A highly portable Forth development
   system based on the ANSI standard for Forth, by Dirk-Uwe
   Zoller of FHT, Mannheim, Germany.  PFE aims to be correct,
   complete, usable, and simple but it isn't optimised for speed.
   It supports all dpANS word sets.  It runs on Linux,
   RS/6000, and HP-UX.
   Tektronix adopted PFE in 1998 and added modules and
   multithreading.  You can load additional C objects at
   run time to extend the Forth dictionary.  It can be
   targeted at different embedded environments by changing the
   terminal driver and initilisation routines.
   (http://pfe.sourceforge.net/).
   E-mail: Guido Draheim .
   (2000-12-07)