The Software Development Kit for iPhone OS was announced at the iPhone Software Roadmap event on March 6, 2008. The SDK allows developers (running Mac OS X 10.5.4 or higher on an Intel Mac) to create applications using Xcode that will natively run on the iPhone and iPod Touch. A beta version was released after the event and a final version was released in July 2008 alongside the iPhone 3G.[12] This major Roadmap event (coupled with a large distribution program for 3rd-party developers), later became known as the iPhone Developer Program, which currently offers two distribution tracks for 3rd-party developers: Standard, and Enterprise.[13]
Applications distributed through the standard program can be sold exclusively through the iTunes Store, on Mac and Windows, or on the App Store on the iPhone and iPod Touch.[13] Developers who publish their applications on the App Store will receive 70% of sales revenue, and will not have to pay any distribution costs for the application. However, an annual fee is required to use the iPhone SDK and upload applications to the store.[12]
Applications developed through the enterprise program are exclusively for institutional use, which allows for large corporations and government agencies to develop more proprietary applications not for public release.[13]
To run an application on the iPhone, the application needs to be signed. This signed certificate is only granted by Apple after the developer has first developed the software through either the US$99/year Standard package or the US$299/year Enterprise package with the iPhone SDK.[12]