Well, the ideal system to me would be:

1) A FORTH VM for hardware abstraction

2) A Smalltalk windowing environment. If the basic Smalltalk ideas
map onto FORTH constructs like code and parameter fields, and
threading, and dictionaries, then it's a done deal to write Smalltalk in FORTH.

3) An APL system coded in Smalltalk. This would be an acid test
because APL HAS to be very fast at moving data, which is what
really takes the most time.