What's the most recent version of AmigaOS?

Question

Simply as the heading states. What is the most recent version of AmigaOS?

Answer 1

A simple question, with a surprisingly complex answer...

Really TL;DR

Hyperion released Hotfix 3.2.2.1 on April 23, 2023

TL;DR

The latest version of each of the main derivates of AmigaOS are:

Branch	Latest version
68k by Cloanto	3.X ROM (45.066) (2016)
68k by Haage & Partner	AmigaOS 3.9 + BoingBag 2 (2002); unofficial BoingBag 3&4 still being updated as of 2022
68k by Hyperion Entertainment	Hotfix 3.2.2.1 (2023)
PowerPC by Hyperion Entertainment	Hotfix for AmigaOS 4.1 Final Edition Update 2 (2021)

In detail

The last version of AmigaOS released by Commodore before their bankruptcy was 3.1. At this point all Amiga models were exclusively on the Motorola 68000 series of CPUs.

After the Commodore bankruptcy, the corporate owner of AmigaOS changed several times. The various new owners did not develop AmigaOS further themselves, but instead commissioned other businesses to do the software development.

At around this time, AmigaOS went in two different directions:

• For the continuation of the 68000-series Amiga computers, the Amiga owners at the time partnered with Haage & Partner to continue the 3.* series of AmigaOS. Haage & Partner released AmigaOS 3.5, and then later AmigaOS 3.9. After that, apart from a series of patch releases to 3.9 called BoingBags, there were no more updates to this line of AmigaOS. This was around the year 2000. The final official release was AmigaOS 3.9 with BoingBag 2 in 2002. After this point, there were some community efforts to continue with bugfixes, resulting in the unofficial BoingBag 3&4, which is still being updated as recently as 2022 by community volunteers.
• Knowing that the 68000 series of CPUs was now EOL, Amiga, Inc. commissioned Hyperion Entertainment to port AmigaOS 3.1 to the PowerPC CPU architecture, beginning the AmigaOS 4.* branch. This began around 2003, and the latest version is Hotfix for AmigaOS 4.1 Final Edition Update 2 in January 2021.

Meanwhile, Cloanto had licensed all the Commodore versions of AmigaOS for distribution with their Amiga Forever product. At this point, AmigaOS 3.1 was aging poorly - it had trouble with hard drives (emulated hard drives, in the case of Amiga Forever) larger than 4GB, and other bugs were affecting it. Cloanto could not develop AmigaOS themselves, but they took the 3.1 ROM and applied some bugfixes and updates to it and in 1999 started their version of the ROM named 3.X. While not a full AmigaOS release (there was no Workbench 3.X), it nevertheless is another branch - the third - in the development of AmigaOS.

Then, around 2018, another branch of AmigaOS appeared. Since PowerPC Amiga hardware was very rare, but there was a growing "retro" scene around the classic 68000-series of Amiga models, Hyperion Entertainment re-opened development based on AmigaOS 3.1 again, releasing AmigaOS 3.1.4. They followed this up with AmigaOS 3.2, followed by some minor releases. The current version is Hotfix 3.2.2.1.