Any opinion on which Forth implementation is good for 8-bit CPUs, in particular 8051?
It's impressive what you can do in the C64 with just Forth instead of C64 Basic.
For Speccy/ZX80/ZX81, I'm pretty sure they ported the Jupyter ACE one, boosting up the available RAM in the 48k and 128k making Basic almost obsolete in that platform.
It's not large.