Tour of Quartz Composer
From QuartzCompositions.com the central source for Quartz Composer :: wiki
This section is based on Apple.com: Tour of Quartz Composer (http://developer.apple.com/documentation/GraphicsImaging/Conceptual/QuartzComposer/qc_concepts/chapter_2_section_1.html#//apple_ref/doc/uid/TP40001357-CH202-TPXREF101) but is meant to be shorter, clearer and expandable.
