
In 2005, when began planning the he had a choice to either “shrink the Mac, which would be an epic feat of engineering, or enlarge the iPod”. Jobs favored the former approach but pitted the and and , respectively, against each other in an internal competition, with Forstall winning by creating the iPhone OS. The decision enabled the success of the iPhone as a platform for third-party developers: using a well-known desktop operating system as its basis allowed the many third-party Mac developers to write software for the iPhone with minimal retraining. Forstall was also responsible for creating a for programmers to build iPhone apps, as well as an within