A set of programs written Pedro Gimeno, and offered under the Expat
license (one of the many MIT licenses).

This package contains three command-line programs:

- JAForth: An interpreter for the Jupiter ACE Forth, written in
Python, that can also compile to a Jupiter-format or Spectrum-format
.TAP tape file.
- jforth: A headless Jupiter ACE emulator which runs the Jupiter ACE
Forth, reading the input from a file and writing the output to
standard output.
- JADecompile: A Jupiter ACE Forth .TAP decompiler.

The first two do more or less the same. While the second was written
with the sole purpose of validating the first, it turned out to cover
almost the same functionality as the Python version.

Which one do you need? Well, the Python version is autonomous - you
only need a Python interpreter in your machine (2.7 or 3); you don't
even need the ACE ROM. Python interpreters come bundled by default
in most systems nowadays, including Linux, Windows, OSX, BSD and
whatnot; if yours is one of these rare cases where there isn't one,
you can grab a pre-built binary or even compile it from source.

On the other hand, the headless emulator (jforth) requires a ROM
(named ace.rom and present in the current directory), a C compiler,
and GNU make to build. The accuracy is of course guaranteed, but
since it was used to test the accuracy of the Python interpreter,
I'd say the Python version is on par in accuracy.

JAForth.py can't run Z80 code because it's not an emulator, while
jforth can. Not that there's much need for that in a tool that is
aimed at compiling, anyway.

JADecompile.py is a simple Forth decompiler. It's not very accurate
but it more or less does the job. Unlike the LIST command, it can
list (to an extent) words defined with VARIABLE, CONSTANT, CREATE
and VOCABULARY, and it can handle multiple vocabularies. It can
detect words created with DEFINER but it doesn't know how to write
them properly (e.g. if they invoke WORD), so it just lists their
parameter field if there's one.