I've searched the forums to see if this has already been mentioned, but I couldn't find anything, sorry if it has already been covered.
I'd like to recommend RUR-PLE as a way to teach kids (and even adults) the basics of python. It is open source software under the GPL and runs in linux (as well as windows, if people want to try it.)
I've used it myself and it gets you instantly noticing the results of your programs and why you're typing in what you're typing.
It kept my attention all the way through, and it's progression rate makes it very easy to learn.
In it's current version there are a couple of very minor problems with it ( in linux you have to change the location of your saved programs and in one of the final lessons a module doesn't work) but it has been redeveloped into Rurple NG. The only problem with rurple ng is it doesn't currently include a lesson plan.
Anyway, I highly recommend rurple as a way to begin programming for anyone (not just kids) and I think it is a perfect IDE for the foundation's target audience.