RETRO is a personal, minimalistic Forth

Permission to use, copy, modify, and/or distribute this software
for any purpose with or without fee is hereby granted, provided
that the copyright notice and this permission notice appear in
all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
OF THIS SOFTWARE.

RETRO 12 is:

    Copyright (c) 2008 - 2023, Charles Childers

Portions of the code derive from RETRO 11, which was:

    Copyright (c) 2008 - 2016, Charles Childers
    Copyright (c) 2012 - 2013, Michal J Wallace
    Copyright (c) 2009 - 2011, Luke Parrish
    Copyright (c) 2009 - 2010, JGL
    Copyright (c) 2010 - 2011, Marc Simpson
    Copyright (c) 2011 - 2012, Oleksandr Kozachuk
    Copyright (c) 2010,        Jay Skeer
    Copyright (c) 2010,        Greg Copeland
    Copyright (c) 2011,        Aleksej Saushev
    Copyright (c) 2011,        Foucist
    Copyright (c) 2011,        Erturk Kocalar
    Copyright (c) 2011,        Kenneth Keating
    Copyright (c) 2011,        Ashley Feniello
    Copyright (c) 2011,        Peter Salvi
    Copyright (c) 2011,        Christian Kellermann
    Copyright (c) 2011,        Jorge Acereda
    Copyright (c) 2011,        Remy Moueza
    Copyright (c) 2012,        John M Harrison
    Copyright (c) 2012,        Todd Thomas
    Copyright (c) 2022,        Rick Carlino

The Free Pascal implementation in vm/nga-pascal is:

    Copyright (c) 2016,        Rob Judd

The Nim implementation in vm/nga-nim is:

    Copyright (c) 2021,        Jorge Acereda