This is really informative. Being able to edit the examples like that reminds me of the W3c site on crack :). It's silly but I think the colors and fonts have something to do with it.

One thing though, on Chrome (Mac 5.0.342.9 Beta), intermittently I can't click next to get to the next slide, I get the following error: /apps/learn/jquery.chili.js:241 Uncaught ReferenceError: $el is not defined. This does not happen every time.