The current iPhone OS prevents third party apps from running in the background. This is why the phone cannot multitask. Apps that come bundled with the device can run in the background while another app is running. The problem is that the iPhone OS' security model is designed to close open programs whenever the user returns to the home screen or answers a phone call. This prevents malware, spyware or viruses from running without the user knowing about it. Of course, it also prevents the phone from multitasking. In the past, other OS upgrades were rumored to contain a multitasking function, but it never came to fruition. Perhaps this time will be the charm.Apple iPhone 3GS Specifications
Apple has come a long way to make up for some of the shortcomings of the iPhone. One major function that the handset cannot do is multitask, but with the release of the 4.0 OS, that might no longer be a problem for users. Tipsters with a track record of being on target in predicting Apple's technological advances are saying that Apple has developed the technology to allow for simultaneous running of third party apps. The Cupertino based firm has developed a method to handle things like security, memory and battery life in a way to make multitasking feasible. Part of the solution is being lifted from the Mac OS X operating system. The word is that the iPhone 4.0 OS still has a way to go before being ready for the handset and more workneeds to be done before the software is released..