[tinco]

You could boot your machine into a LISP or Scheme repl, which in my opinion (as a ruby programmer by trade) are much nicer for kids to learn programming with than Ruby or Python because of the dynamic and interactive nature of lisp.

[zokier]

If you are going to take the LISP route, wouldn't booting into emacs and slime make sense?

emacs as a login shell.... I wonder if anyone actually does that :)

[evincarofautumn]

I have experimented with it. The worst problem I had was that the terminal emulators were too slow for my taste. But overall, Emacs works surprisingly well for it.

[eschulte]

If taking this route, maybe emulating one of the old lisp machines would be a good way to go (since they really were lisp all the way down). It looks like someone has already started this project. http://www.unlambda.com/l-machine/l-machine.html