The historical title Doom has been available for some time as open source software, so it is completely free and available to programmers who want to use its code. The two programmers interviewed from 9 to 5 Mac are indicated exclusively with their nicknames: Stepwhite and Psychochromatic. The porting of Doom on the iPhone started between a joke and a bet: Stepwhite had recently purchased an iPhone, so the programmer friend has it challenged to run the game on the iPhone in a single week, a conversion limited to operation only, without having to implement any new control system. More than a bet, a joke. A week later for Stepwhite he returned with the game working and a link to the Internet page dedicated to the project: the first version was downloaded by 15 thousand people despite not having a control system. The project went on once the command system was introduced and the game was downloaded by 25,000 people.
The two programmers claim that the ease and short time required to port the game is all about the platform: "iPhone works with Mac OS X. It is a complete UNIX system in your pocket …" in which the Objective C environment is available which it also facilitates the development of complex applications. Many of the iPhone APIs are identical to those used for Mac OS X programs, so there is no need to re-learn all over again for those who already know the environment. Still, according to the game's programmers, the release of the SDK for iPhone by Apple has prompted several Windows developers to learn the languages of the Mac world, in particular Objective C and Cocoa. For these people, once you become familiar with iPhone, it will be easier to program also for Mac OS X.
On the other hand, the opinion on Apple's choice to limit access to some programming APIs is less positive: the same Doom for iPhone uses APIs indicated as private and cannot be used by third-party programmers to speed up some drawing operations. For Apple to decide to promote Doom for Iphone and enter it in the APP Store, making it in fact available for everyone, the two developer friends will be forced to rewrite the portions of code that now exploit the "prohibited" APIs. The problem of APIs reserved only for Apple, however, could also limit other projects, for the development of programs that require more direct access to the iPhone operating system.
Always according to the programmers interviewed, unlocking the iPhone will always be used, at least until iPhone is sold "free" because it represents the only way to avoid the expensive rates imposed by the operators. Finally, a judgment of the two on the iPhone and the future of the device: “IPhone combines the popular image and brand excellence (Apple, editor's note) with the most powerful and fun operating system available for mobile devices. The possibility of having the latest version of iPod that can also manage all the speech and the Internet in a single device, are factors that will be very interesting. Every person who tries it wants to own one, this fact alone makes it superior to any Windows Mobile device or to Nokia smartphones on the market ".
The iPhone conversion of Doom made by Stepwhite and Psychochromatic available on this web page.