AmigaOS is the default native operating system of the Amiga personal computer. It was developed first by Commodore International, and initially introduced in 1985 with the Amiga 1000. Old versions only run on the Motorola 68k series of 16-bit and 32-bit microprocessors, while the newer AmigaOS 4 runs only on PowerPC microprocessors.On top of a preemptive multitasking kernel called Exec, it includes an abstraction of the Amiga's unique hardware, a disk operating system called AmigaDOS, a windowing system API called Intuition and a graphical user interface called Workbench. A command line interface called AmigaShell is also available and integrated into the system. The GUI and the CLI complement each other and share the same privileges.The current holder of the Amiga intellectual properties is Amiga Inc. In 2001 they contracted AmigaOS 4 development to Hyperion Entertainment and in 2009 they granted Hyperion an exclusive, perpetual, worldwide right to AmigaOS 3.1 in order to develop and market AmigaOS 4 and subsequent versions.