This sounds interesting. Mac or PC friendly.

from their site:
About Kidos
Kidos is a revolutionary new platform for children’s learning and entertainment. Our free and easy download allows a child to use her parents’ computer as if it were her own! No more having to worry about files being accidentally deleted, settings being changed or kids closing the browser by mistake. No more cries of “Mommy!” every time he clicks the “back” button by mistake or the internet connection is slow.
Our secure, child-friendly and lightly animated interface lets children easily use all sorts of media: games, books, learning modules, music, video, and art. Best of all, it works on either a Mac or PC and…it’s free! You can also easily add your own music, art, photos, and video!
We’re busy aggregating the best children’s media from all over the world. Want to help your child learn a foreign language? You’ve come to the right place!
Kidos is currently in private beta. To take part in the soon to be released public beta, please sign up and we’ll notify you soon!