The iPhone SDK: First Thoughts

Yesterday, Apple unveiled the software developer kit for the iPhone. A lot has been written about this already. As always, John Gruber has a comprehensive overview.

Here are my thoughts on this:

  • First of all, interest in this seems to be tremendous. Yesterday, after the announcement, something happened which I’ve never seen before: Apple’s dev servers went down under the onslaught of interested developers.
  • All iPhone applications will be sold through Apple’s store. There’s no other way to get on the iPhone.1 Apple has some general rules about what applications they accept; the rules, however, are somewhat unclear. Apple has said that they won’t allow porn and malicious applications. Ryan Block asked whether they would allow SIM unlocking software. The answer, of course, was no. While it was fair to ask the question since it forced Apple to clearly come out against SIm unlocking software, I would have preferred if he had asked something a bit more interesting. For example, Apple has stated that their store is the only way to get software on the iPhone. Does that mean that a third-party application would not be allowed to install software? This question might seem a bit dumb at first, but package management systems like Fink or DarwinPorts are valid third-party applications which - on the Mac side at least - are even supported by Apple. Will they not be allowed on the iPhone?
  • Will the iPhone Human Interface Guidelines be enforced, or are they optional? The guidelines say that «Only one iPhone application can run at a time, and third-party applications never run in the background.» This means something like an AFP server is out of the question. A specific iPhone application idea I’ve been contemplating is a kind of ad-hoc mobile social network. The application would periodically send your position to a server, and would then be able to tell you about people using the application near your location. Such an application would need to be running in the background; it seems Apple would not accept this.
  • The application I mentioned above highlights another issue: Presumably, Apple will not allow demos which can be turned into full versions by directly buying a serial number from the developer since that goes around Apple’s store. Further, Apple will probably not allow software which is free by itself, but requires some kind of subscription that is paid to the developer.
  • Seems Apple mainly spent the last year making formerly public APIs private. Compared to the «unofficial» SDK, Apple’s official SDK can do a lot less. This could mean two things: Either Apple doesn’t want developers to do the things they removed from the public API, or they aren’t yet happy with the interfaces and want to stabilize them before they make the applications public. Also, official third-party applications are forbidden from using private SDKs.
  • I’m a registered SonyEricsson developer. Interestingly, just after the Apple event, SE started running a survey «on the quality and relevance» of their worldwide developer programs
  • Finally, it seems I was right in my prediction that Apple will enforce compliance to API rules not through a sandbox, but through its approvement process.

All things considered, the official SDK is a mixed bag. It’s better than some people feared, but worse than some people hoped. Hopefully, Apple will open iPhone development further at some later date.

Further Reading

TidBITS has an extensive article on the subject, while Ars Technica provides a short summary. Macworld has some developer reactions, which typically range between «goodness» and wanting to kiss Steve Jobs «full on the mouth


  1. Well, that’s not entirely true. There are two other official ways to get an application on the iPhone: Using Apple’s SDK so you can test your app, and (presumably) using some kind of Enterprise deployment system. And of course, there will be unofficial ways, too. back

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