A few developers have complained about the wording in the terms of Apple’s SDK that restricts them to one iPhone application running at a time. Dan Dilger at Roughly Drafted on Thursday said it’s only partly true and some developers have misinterpreted the statement.

Everyone knows that the version of OS X in the iPhone is Unix. So why would Apple restrict developers, as they have, in the terms of its SDK, Mr. Dilger asked.

In order to explain what Apple is up to, Mr. Dilger took a look at the problems of WinCE and how, on paper, it looks good but fails in practice. "...WinCE proves that the general idea of having no limitations on third party background processes and concurrently running applications on a handheld device is a bad idea." The observations on Mr. Chris De Herrera, knowledgable about WinCE were cited.

"There are times when having multiple applications running at once causes the foreground application to slow down noticeably. This slowdown is due to the amount of time that the operating system is spending servicing background applications. In these instances, I recommend that users consider performing a soft reset."

The true operation of the iPhone is explained in a little more detail. In fact, applications can suspend and resume after a phone call and are not obliterated. In the current version, the iPod portion can continue to play music while one is surfing in Safari, so the iPhone certainly is using multitasking. The question really goes to the restrictions Apple has placed on developers to make sure the iPhone operates responsively.

The license Microsoft has given to apps in WinCE allow any app to hog the processor and bring a WinCE smartphone to its knees, and, basically, Apple wants to avoid that scenario by placing some minor restrictions on first generation iPhone native apps. The concerns of some developers are overblown, according to Mr. Dilger.