iPhone SDK raises more questions than it answers.

Well, the battle to get 3rd party applications onto the iPhone is not over yet, especially for VOIP applications. In one specific way, the SDK actually closes the iPhone platform rather than opening it up to innovation. An explanation is in order.

First, let's look at the list of restrictions that the SDK imposes on application development as they pertain to VOIP (from WIRED):

1. No VoIP Apps on EDGE Ñ Any VoIP app will only be able to run via a WiFi connection since allowing them on EDGE would effectively destroy AT&TÕs revenue (and AppleÕs cut).
2. Only Apple Approved Code Ñ The SDK Agreement reads: Òan application may not itself install or launch other executable code by any means, including without limitation through the use of a plug-in architectureÉÓ Which eliminates Firefox, Thunderbird, MS Office, Photoshop and host of other applications. Of course these apps could be crippled to turn off the plug-in aspects, but that isnÕt likely to happen.
3. No Background Processes Ñ The SDK also mandates that applications must quit when dismissed by the user Ñ in other words there will be no background processes. That eliminates the possibility of a geo-data updater running in the background, reporting your location back to a web service. Ditto for any other Òauto-updatingÓ application.
4. Applications are sand-boxed Ñ The SDK reads: Òan application may write data on a device only to the applicationÕs designated container area, except as otherwise specified by Apple.Ó That means apps canÕt share data and the possibility of cool mashups is basically eliminated.
5. Only Official APIs Ñ The last noteworthy (though expected) limitation is that applications Òmay only use Published APIs in the manner prescribed by Apple,Ó which means all the cool stuff the jailbreak developers have discovered is out the window.

On the other hand, restriction #3 (no background processes) is very much of a problem for VOIP. It's an odd restriction because VOIP almost by definition depends upon background processes... it needs to log into the network and be prepared to receive calls while the device is involved in other activities. Listening is by definition a background process. There is hardly any point to a VOIP phone that can't listen for inbound traffic.

So why did Steve Jobs declare to the world that VOIP applications were welcome on the iPhone? It makes no sense to me. Here are some possibilities:

• It is all a misunderstanding; the rules that were released don't mean what they appear to mean.
• The SDK's rules are going to change between now and June. Apple has a long history of changing its mind on things, especially on products that are clearly still in beta.
• Apple wants VOIP developers to come to them to negotiate a special deal so as to allow background operation.
• Apple intends to invite only a crippled facsimile of VOIP onto the iPhone, but not VOIP itself. Maybe they want only chat clients, or maybe only outgoing calls. It is inconceivable.

In any case, the picture is very muddy because the SDK's rules appear to directly contradict Apple's public statements. Hopefully some VOIP developer (Skype perhaps) will test the waters with Apple and discover what they really intend. I don't know what it is, but I do know that Apple would be unwise to stop VOIP from coming to iPhone.