9.4. App As OS

Apple requires that applications not compete with the suite of applications that make up the default user experience. Applications are often rejected for duplicating functionality already supplied by Apple. This means that the market will likely never see real competition for the iPod application, Mail, or Safari, among others.

There are many ways of looking at this policy. One non-cynical view is that competing applications hurt the overall user experience. Instead of building a competitor to Safari, for example, developers can provide links that will open Safari, letting the most capable application handle the task at hand. As another example, you can enable users to send an email by making calls to load a URL with the mailto:// URL scheme, which is intercepted by the Mail application. With the right arguments in the URL, the Mail application will instantly craft a message with a subject, a recipient address, and even a message body.