On Thursday, 15 March 2012 at 07:09:39 UTC, so wrote:
If so Lisp will be my first choice.
I just talked about D because D rox, but if you are doing it for education, Lisp is a good choice because it is fairly unique. For real jobs, I'd go with D or maybe Javascript if I wanted scripting. (Javascript isn't a great language, but it is good enough, well supported, and popular; people can pick it up and go pretty easily. I've previously used Lisp for scripting - you can make a Lisp interpreter in ~1,000 lines of code - but JS has decent interpreters out there too.) But for education, Lisp's uniqueness is a good thing - experiencing the new syntax and playing with the macros is a good way to learn things you might have not looked at otherwise. So I'll second Lisp if you don't want to play with D.