OOP the Easy WayObject-Oriented Programming the Easy Way: a manifesto for reclaiming OOP from three decades of confusion and needless complexity.
Actually Graham, I would be surprised if there is any GPL code there.
Apple have become utterly paranoid about GPL since GPLv3. Look at how much stuff has either stayed at a fork of the GPLv2 instance or has been abandoned altogether.
They’re even unwilling to distribute pkgs of GPL code you have given them back to you as part of their CSS Enterprise Imaging product.