NSWindow Mac App Store like Title Bar

How could I make an NSWindow's title bar look like that of the Mac App Store or of the app Feeder where it's height is increased and other controls are show in it.

To see what I mean just check out the website for the Mac App Store : http://www.apple.com/mac/app-store/.

Is it a custom NSWindow or is it a completely borderless window with an NSView made to look like the title bar?