Ever since I started using AREXX, I developed strong ideas on what
feautures make a Rexx Host. Rather than to simply say what I want, I
decided to put together an example.

    Actually, last year I started adding a bi-directional Rexx port to
DME. But <.....>        had already added a
a Rexx port, and in a way that was incompatible with my then version.
So I cancelled my project. Finding nothing else to do during this
summer, I decided to create an example out of it. Mainly I want to be
able to say, "If I can do it, so can any programmer". In the meantime,
I also had the opportunity to look at the proposals of <..............>
on adding a rexx port to MicroEmacs, and at Tom Rokicki's version of
FreeDraw.

Now, let me list the levels of Rexx support a program may have:

    1(a). ARexx is a glorified macro processor cum variable handler.
    1(b). Commands will also be accepted from ARexx.
  However the program does not have both 1(a) and 1(b).

    2. The program exists in two modes: In the active mode, 1(a) is
    supported. In the idle mode 1(b) is supported.

    3. Full bidirectional support is there. [If that is the case, support
    for asynchrnous arexx invocations may also be given.]

Tom's FreeDraw does all three. But I want a few more features:
    Firstly, there should be a way to control the access. My suggestion
would be to have paswords. External commands must be prefixed with the
password while the restriction is in effect. Restriction placed by
the user at the console must take precedence over others.
    The macro invocations must allow for function invocations, for
result strings to be requested, or command line tokenization etc.
    No commands must be carried out after the program reaches the
halt condition: This when the halt command is recieved from the console
but before the program has cleaned up after itself.

    I have written a proof-of-concept example. I have tried to make the
code as reusable as possible. But right now the code is Manx-specific.
But one should be able to convert it other compiler/assembler combos
in a dozen or so man-hours. If you plan to implement the full functionality
of this example, I will gladly donate my help [even if you will profit
from it].