I heard about it a while ago, but it was not until your post that I thought "Duh! this might be the thing to throw at my brother." - he's currently playing with HTML+JavaScript, which isn't really the best way to learn to program (bad syntax checks etc.)
I had thought about C/C++, but well... he wants to play around with graphics, and to do that in C/C++ I'd have to write up a whole little framework for him -