Running subprocess in iOS?

Is it possible to launch a new sub-process in iOS? (f开发者_如何转开发rom regular application) If possible, how to do that?

While it may be possible with jailbreak apps, the SDK does not allow that. You are only allowed your own application's process. It can operate in the background (for a limited amount of time) and/or have however many threads of its own as you say, but they all have to belong to that one process.