"One of the most frequently used Cocoa classes is NSImage which, as the name suggests, is all about displaying and manipulating image data.
The imageNamed: method of this class retrieves an image reference for you - provided that you know the name of the image you're after.
Many of the images that can be retrieved via the imageNamed: method have well documented names, but there's a lot of stuff in there that's not well-known.
It's those images - including some for Windows - that I'll be digging into here.