Hmm, the turtle demo is barely usable on the mac:

* The "Choose Example from Menu" is a label and not clickable.
* The left pane is clickable but does nothing.
* When code is chosen from the menu the font-size is small.
* The "start" button label is invisible and the "stop" and "clear" buttons are barely visible with yellow-on-white.
* Once started, the "stop" button is invisible and the other two buttons shift to yellow-on-white.