[syntheweave]

You could definitely argue that it would be better to build off of something like Contiki, a modern small-device OS that gained a lot of fame for its ports to old microcomputers, but is currently active in industry as well, with a new "Contiki-NG" version.

The appeal of Forth is mostly in a principled sense of, if you want Forth to be your interface, you have to build your own Forth, because Forth does as little as possible to structure you. And building your own Forth is not impractical; that's the whole point. It's wonderful as an exercise and can be productive in the right context.

But any highly developed or standardized Forth system gradually converges on being "just another platform." And once it's just another platform, it's an annoying dependency, and you end up demanding more structure for it to help tame the complexity, so the Forthiness habitually erodes.

[vidarh]

I couldn't imagine using Forth for all of my programming, but personally I quite like the thought of underpinning a more complex system or language with a small language like a Forth or Scheme, or just something borrowing key elements. Use them to shape the basic structures at a level where they excel, and then put one or more other options on top, and interfacing with a layer far more pleasant than a bare machine.

E.g. for my experimental long-languishing Ruby compiler I bootstrapped a tiny typeless s-expression based language - not a lisp/scheme, just borrowed some syntax - to let me "escape" the warm embrace of Ruby to bootstrap the basics. It wasn't very carefully planned, and there are many things I'd like to change when I get time to play with that project again (it's been literally years, but it's not forgotten), but that aspect is part I still like, though I might like to change parts of that low-level language too.