Ward Cunningham's DSL for teensy microcontrollers
github.com
github.com
Perhaps it's because of the AT90USB162's RAM restrictions (512 bytes), but it seems having a "stack" of just one item and non-nestable loops is pretty restrictive. Oh, and no + - * / operators.
I don't think adding nestable loops and a stack of say 5 items (10 bytes of RAM) and math operators would hurt much, and it'd certainly add to the power of a language like this -- perhaps changing it from a tiny debugging tool to a useful "scripting" language.
http://amforth.sourceforge.net/
or:
The times they are a-changing.