Is Quartz programming consistent between iOS and OS X? I'm looking for a good book on Quartz and came across one for Mac OS X but am only building for iOS. Since some APIs are different, such as OpenGL, I'm wondering if the same applies to Quartz?
No, Quartz seems to be very similar, if not identical. Coordinate systems are the same, with the origin in the lower left.
I'm not aware of any differences. Even bugs are identical.