The way this article is written is highly misleading.
> iOS for mobile devices Apple, well, created iOS for mobile devices. It did not rewrite the OS X desktop that runs on Macs. Apple created something entirely new that was always designed with touch screens in mind.
Except that is untrue. Or to quote Apple during the iPhone's initial release:
> iPhone uses OS X, the world’s most advanced operating system.
What later became known as "iOS" is based on OS X which is its self based on Darwin. You could fairly argue that OS X for the i-devices was a fork but to say Apple made something "entirely new" is just false.