The A4000 shipped with AmigaOS 3.0, consisting of Workbench 3.0 and Kickstart 3.0, which together provide a single-user multi-tasking operating system and support for the built-in hardware.
Following release of AmigaOS 3.1 it became possible to upgrade the A4000 by installing compatible Kickstart 3.1 ROM chips.
The later AmigaOS 3.5 and 3.9 releases were software-only updates requiring Kickstart 3.1.

AmigaOS 4, a PowerPC-native release of the operating system, can be used with the A4000 provided a CyberStorm PPC board is installed.
Likewise, MorphOS, an alternative Amiga-compatible operating system, can be used with this hardware.

Variants of platform-independent operating systems, such as Linux and BSD, can also be used with the A4000.
The A4000 shipped with AmigaOS 3.0, consisting of Workbench 3.0 and Kickstart 3.0, which together provide a single-user multi-tasking operating system and support for the built-in hardware. Following release of AmigaOS 3.1 it became possible to upgrade the A4000 by installing compatible Kickstart 3.1 ROM chips. The later AmigaOS 3.5 and 3.9 releases were software-only updates requiring Kickstart 3.1.
AmigaOS 4, a PowerPC-native release of the operating system, can be used with the A4000 provided a CyberStorm PPC board is installed. Likewise, MorphOS, an alternative Amiga-compatible operating system, can be used with this hardware.
Variants of platform-independent operating systems, such as Linux and BSD, can also be used with the A4000.
Amiga 4000