probably what makes is good learning material is that I am learning
myself, so it demonstrates some basic functions well I think, but is
still just scratching the surface of picolisp.
I wrote it for a console-only handheld with a very small screen, so
wanted it keystroke driven (raw mode) as well as to keep typing in
general down to an absolute minimum, just to be easy and fast.
its niche is for when "a bit of menu" is all you need. ;)