APL has run native if I'm not mistaken, and is an odd language by most programmers' definitions.
I suppose much of the system would have been written in assembly language, but there's always a point where features may just as well be coded in the high-level language.
Schol-R-LEA wrote:Similarly with FORTH, which while a definite stand-out in uniqueness, was specifically designed for systems and embedded programming (it was initially used for controlling radio telescopes).
Yeah. Forth
looks very strange, but it's a good match for many low-end architectures of the 70s 80s & 90s. The abundance of registers in newer designs might seem to obsolete it, but the registers can be used with some fairly simple optimizations. That said, it is a strange langauge to work with if you try to use it as its inventor intended: with very small definitions and without local variables. Large definitions can be impossible to debug. Local variables are very difficult to fit into a traditional, Forth system. The best I've seen put the local variables on a 3rd stack, requiring redundant memory copies where Forth otherwise requires less memory copies than a pass-by-value language.
The inventor of Forth later quit the language and wrote a GUI OS directly in machine code.
Then he did it again, this time with no GUI but a very strange implementation of Forth for scripting. All the text was Shannon-coded, and there was something about the coded definition names themselves being the code. Anyway, this Forth is known as colorForth, but the OSs are OKaD and OKaD2.
Where's @DavidCooper? He's written an OS in machine code too, and he prefers decimal to hex.
But the
real answer to the OP's question would be an OS written in an
esolang.
Unfortunately, searching the Esolang Wiki only turns up a
thought experiment. Someone ought to just go ahead and do it. I have had thoughts of doing it myself, using one of those languages in which the program exists on a 2D grid and choices are made as conditional
turns left or right.
I have enough trouble getting on with a more normal project, though.
LOL! The Esolang Wiki has a page on
Forth. Of course it does.
I have also
considered daydreamed about an OS implemented as a spreadsheet. I mean, a spreadsheet is basically a functional programming language, so why not?