Besides mentioning this at the debut of WWDC '08 yesterday, Apple has also issued an official report noting that its iPhone Software Development Kit, or SDK, has been downloaded more than a quarter of a million times since its initial release in March. Philip Schiller, Apple's senior vice president of Worldwide Product Marketing, explains:

"Developer reaction to the features, power and simplicity of the iPhone SDK has been incredible." Schiller then went on to say that "We are seeing some truly amazing native apps from our developers and think users are going to love the breadth and depth of the applications available from the App Store."

Renowned developers such as AOL, Cisco, eBay, Electronic Arts, Epocrates, TypePad, Salesforce.com and Sega have demoed their native iPhone apps on stage yesterday. The apps were, of course, developed using Apple's iPhone SDK. Sega's iPhone version of Super Monkey Ball, for instance, was first showcased at Apple's iPhone Software Roadmap event back in March. In two weeks, Sega's developers managed to get a tremendous amount of gameplay elements up on that port, something that wouldn't have been possible had it not been for Apple's SDK.

Now, just over two months later, SEGA has a full version of Super Monkey Ball sporting breathtaking graphics, game physics and the most intuitive control scheme for a game of its kind. Best of all, SEGA's game has now a total of 110 challenges (levels) awaiting to be overcome by iPhone / iPod touch owners worldwide.

This was possible only because the iPhone SDK provides developers with the same rich set of Application Programming Interfaces (APIs) and tools that Apple uses to create its native applications for iPhone. The toolkit is strongly connected to Apple's upcoming App Store, through which apps developed with the SDK will be made available, either for free, or at a cost.

Developers throwing their software onto the App Store may choose to set a price point per download, but they may also opt to allow every handset user to download that content for free. Apple, however, encourages devs that they charge a fee, be it a small one, to help support and maintain the hosting of software on the App Store. By charging for an app, developers get 70% of the revenue, while Apple gets the remaining 30%, to be used for the maintenance of the App Store.