iPhone OS is the operating system running on the iPhone (both original and 3G models) and the iPod Touch. It is based on a variant of the same basic Mach kernel that is found in Mac OS X. iPhone OS includes the software component “Core Animation” from Mac OS X v10.5 which, together with the PowerVR MBX 3D hardware, is responsible for the interface’s smooth animations. The operating system takes up less than half a GB of the device’s total 8 GB or 16 GB storage. It is capable of supporting bundled and future applications from Apple, as well as from third-party developers. Software applications cannot be copied from Mac OS X but must be written and compiled specifically for the iPhone.