AmigaOS

Early versions of AmigaOS required the Motorola 68000 series of 16-bit and 32-bit microprocessors. Later versions were developed by Haage & Partner (AmigaOS 3.5 and 3.9) and then Hyperion Entertainment (AmigaOS 4.0-4.1). A PowerPC microprocessor is required for the most recent release, AmigaOS 4.

AmigaOS is a single-user operating system based on a preemptive multitasking kernel, called Exec.

It includes an abstraction of the Amiga's hardware, a disk operating system called AmigaDOS, a windowing system API called Intuition and a desktop file manager called Workbench.

The Amiga intellectual property is fragmented between Amiga Inc., Cloanto, and Hyperion Entertainment. The copyrights for works created up to 1993 are owned by Cloanto. In 2001, Amiga Inc. contracted AmigaOS 4 development to Hyperion Entertainment and, in 2009 they granted Hyperion an exclusive, perpetual, worldwide license to AmigaOS 3.1 in order to develop and market AmigaOS 4 and subsequent versions.

On December 29, 2015, the AmigaOS 3.1 source code leaked to the web; this was confirmed by the licensee, Hyperion Entertainment.

AmigaOS is a single-user operating system based on a preemptive multitasking kernel, called Exec. AmigaOS provides an abstraction of the Amiga's hardware, a disk operating system called AmigaDOS, a windowing system API called Intuition and a desktop file manager called Workbench.

A command-line interface (CLI), called AmigaShell, is also integrated into the system, though it also is entirely window-based. The CLI and Workbench components share the same privileges. Notably, AmigaOS lacks any built-in memory protection.

AmigaOS is formed from two parts, namely, a firmware component called Kickstart and a software portion usually referred to as Workbench. Up until AmigaOS 3.1, matching versions of Kickstart and Workbench were typically released together. However, since AmigaOS 3.5, the first release after Commodore's demise, only the software component has been updated and the role of Kickstart has been diminished somewhat. Firmware updates may still be applied by patching at system boot. That was until 2018 when Hyperion Entertainment (license holder to AmigaOS 3.1) released AmigaOS 3.1.4 with an updated Kickstart ROM to go with it.