When all we had was Mac OS X (now macOS), our Mac life was simple on Intel-based Macs. Then came iOS with Cocoa Touch, a derivative of macOS for touch devices using ARM CPUs. That seemed so very sensible in 2010. Then, of course, came tvOS and watchOS which means Apple has even more code bases to maintain. While perhaps only a mild burden, the biggest problem may be the future development of Apple devices. John explains.