X code program (a set of related programs working together) used by programmers (in fact, software engineers and developers) to write software for Mac OS X, iOS (iPod, iPhone, iPad), Apple Follow and now Apple TV.

X code is a kind of IDE package called Integrated Development Environment with publishers, compilers, and other software tools that work together to help the software to write, compile, upload to the device, debug and send it to the App Store Or anywhere).