Picol is a Tcl-like language written in 587 lines of C code, written by Salvatore Sanfilippo.
Porting it to the Pico proved straightforward. I made only minor tweaks, like getting the serial port to echo the input.
It’s a very barebones implementation, but looks useful for embedding in the Pico as a control language. Extend it however you want.
Why not Forth? Well, that’s a logical choice, of course, but I’m having trouble porting over some code. I’ve not yet been able to produce working code.
Checkout the code here. Happy hacking.