The rest of the storyline of this page covers what I think is the core concept that Chuck Moore started from, and defines Forth as its own environment: the core of the language that needs to be defined in order to write and execute Forth words is surprisingly small. Once you have the core words in place, you can layer on exactly the constructs you need.

I won't claim to be a proficient Forth author, but I've used it to accomplish a couple of rather odd one-off projects, and it is amazing how much you can do, as long as you're not expecting graphics or networking or huge storage needs.

Compactness matters because when you're trying to bootstrap into a tiny (or hacked together custom build) environment, the tiny bootstrap footprint means you can be up and rolling that much faster.

C is all good, I've been writing it for a long time, but I'd much rather get a Forth core going in raw assembly than even a stripped down to brass tacks C compiler.