By this part of the book, it's assumed you are on your way to mastering everything about using Mac OS X that there is to know. Now maybe you'd like to consider tinkering with development. Your Mac provides a wonderful platform for development whether you are doing Unix shell scripting and web development or you creating the next must-have iOS or Mac OS X application.
Part IX provides an overview of the technologies and tools available on Mac OS X for the seasoned or aspiring developer.