The real special sauce for Forth is that it's small and it's knowable. Anyone who wants to learn about how elegant a computer system can be should take a look at jonesforth[0], a Forth implemented in x86 assembly language. It really is possible for a programmer to easily understand everything a Forth does, which is wonderful when writing a bootloader or low-level OS.

In a lot of ways, it's a more-structured assembly language.

TCL could be cool for a low-level system too, as could be a Lisp (also: how can anyone hate Lisp with a passion‽‽‽), as of course could be Forth. Perl & Python are too big and not minimal enough.

0: https://github.com/nornagon/jonesforth/blob/master/jonesfort...