[rasz]

Its a $4 part doing 40MB/s over USB 2.0, hard to beat even 20 years after it was introduced.

[eqvinox]

I'm not disputing that. It can be a performant USB implementation and using an awful core that should've died out 10 years ago at the same time. Like, you can fireproof your house with asbestos, it works great. Still wouldn't recommend it, for, uh, reasons ;)

[LargoLasskhyfv]

There are excellent FORTHs out there, for 8051 and derivatives.

If not, it should be easy to bootstrap one.