Talking of Forth, it is worthwhile to note that Postscript as implemented by Adobe for laser printers and subsequently for photo-typesetters, etc is a very good example of Forth-like system running on bare metal and providing an application specific programming + operating environment.

Years ago, Byte magazine published an excellent book "Threaded Interpreted Languages" (TIL) which contains lots of good information, including details of how to roll your own using the Z80 (yes, the book is that old).

On 27 June 2018 at 15:18, Iruatã Souza <iru.muzgo@gmail.com> wrote:

On Wed, Jun 20, 2018 at 10:39 PM, Kurt H Maier <khm@sciops.net> wrote:
> On Wed, Jun 20, 2018 at 10:35:42PM +0100, Ethan A. Gardener wrote:
>>
>> a sort of operating system where the primary interface to all tasks is
>> a Forth interpreter.
>
> I think we've talked about this in another venue some years back, but I
> often thing of the OpenFirmware implementation used by the OLPC XO-1
> laptop. Instead of a BIOS or UEFI or linux trash in their stead, the
> system was managed by an OpenFirmware installation, much of which was
> written in Forth, and whose primary interface was a Forth shell. This
> environment had complete access to the hardware of the system, which
> was used by the project to create really comprehensive hardware
> diagnostics tools.
>

Kurt and Ethan,

I am sure you know that, but Forth has basically started as an
language + operating system and stayed there for quite some time.
Forth hosted on other operating systems is the (not so) new thing.

For a "recent" instance of Forth language+os for the pc, check Andy
Valencia's ForthOS.