Apple's iPhone OS version 4.0 is not yet released, but it has already been jailbroken.
The team behind the redsn0w jailbreaking app have released a beta version for iPhone OS 4, 9to5macreported.
The beta is currently available only for jailbreak app developers so they can prepare apps for the upcoming release, and currently only supports Mac OSX, the iPhone 3G handset and beta 1 of the iPhone OS 4.0 software, Engagetsaid.
In another potential blow to Apple's plans for its mobile devices, an independent developer has added limited multitasking support to the iPad via an app available on the iTunes store.
Mulitasking for iPad allows users of the iPad to run Facebook, Twitter and Safari at the same time.
Early reviews of the app have been positive, confirming that the app allows true simultaneous use of all three applications.
Apple has yet to confirm when (and if) the multitasking support introduced in iPhone OS 4.0 will be added to the iPad.