EForth is a delightfully minimalist approach to Forth originated by Bill Muench and Dr. C. H. Ting.
ESP32forth - Version 6.3 for NodeMCU ESP32S - Tweaked for the Web
ESP32forth-6.3.0.ino - This has Dr. Ting's v6.3 version with WebUI added in to it.
EForth exclusively uses FOR..NEXT in favor of DO..LOOP.
Details
This construct has the odd property that it iterates one "extra" time for zero.
: FOO 10 FOR R@ . NEXT ; FOO 10 9 8 7 6 5 4 3 2 1 0 ok
To permit a more ordinary loop the AFT word is used in the sequence
FOR..AFT..THEN..NEXT.
: FOO 10 FOR ( 1st time only ) AFT R@ . THEN NEXT ; FOO 9 8 7 6 5 4 3 2 1 0 ok
The even more enigmatic FOR..WHILE..NEXT..ELSE..THEN
is used in place of DO..LEAVE..LOOP.
It allows a while condition to early out of a counted loop.