MacOS X is based on several layers. On top of Darwin sits a layer of BSD libraries and utilities. Quartz natively displays OpenGL for 3D graphics and animation, QuickTime for full-motion video and sound, and also allows the stunning Aqua interface design.
Programmers can write for OS X for five main environments.
Carbon applications can be run on older OS 9 systems as well as take advantage of the modern OS X features. Finally, they can develop and deploy object-oriented Java applications with WebObjects, with all of the simplicity and power of the Cocoa environment. All of Apple's technical documentation and developer documentation is available online, free of charge. Most graphics designers and publishers use Macintosh because of its superior color-calibration system. The ColorSync system automatically adjusts for the differences between different brands of scanners, displays, and printers, so that colors and contrast remain true to the original - from the first scan, to the final print run.