AmigaOS 4 version history

A new version of AmigaOS was released on December 24, 2006 after five years of development by Hyperion Entertainment (Belgium) under license from Amiga, Inc. for AmigaOne registered users.
During the five years of development, users of AmigaOne machines could download from Hyperion repository Pre-Release Versions of AmigaOS 4.0 as long as these were made available. As witnessed by many users into Amiga discussion forum sites, these versions were stable and reliable, despite the fact that they are technically labeled as "pre-releases".
The last stable version of AmigaOS 4.0 for AmigaOne computers is the "July 2007 Update", released for download 18 July 2007 to the registered users of AmigaOne machines.
AmigaOS 4 Classic was released commercially for older Amiga computers with CyberstormPPC and BlizzardPPC accelerator cards in November 2007. It had previously been available only to developers and beta-testers.
4.0 versions.
The new version is PowerPC-native, finally abandoning the Motorola 68k processor. AmigaOS 4.0 will run on some PowerPC hardware, which currently only includes A1200, A3000 and A4000 with PowerPC accelerator boards and AmigaOne motherboards. Amiga, Inc.'s distribution policies for AmigaOS 4.0 and any later versions require that for third-party hardware the OS must be bundled with it, with the sole exception of Amigas with Phase 5 PowerPC accelerator boards, for which the OS will be sold separately.
AmigaOS 4.0 Final introduced a new memory system based on the slab allocator.
Features, among others:
Developer pre-releases.
AmigaOS 4.0 (Developer Pre-release).
The developer pre-release version was a snapshot of AmigaOS 4.0 for AmigaOne. It contained HTML installation guide in English, German, French and Italian and the AmigaOS 4.0 SDK.
The AmigaOS 4.0 SDK allowed creation of new software and migration of existing AmigaOS versions 3.x source code to OS 4.0.
AmigaOS 4.0 (Developer Pre-release Update).
AmigaOS 4.0 Developer Pre-release Update came in the form of a full ISO image (?33 MB) which needed to be burned on CD-R(W) by the user and was intended to replace the original AmigaOS 4.0 Developer Pre-release CD for installation and for rescue purposes.
Release date: 10 October 2004.
Among the features:
AmigaOS 4.0 (Developer Pre-release Update 2).
AmigaOS 4.0 Developer Pre-release Update came in the form of a free download for registered users. The update featured a USB stack update (i.e. mass storage support) and numerous bug fixes and enhancements to core components of the system.
Release date: 27 December 2004.
AmigaOS 4.0 (Developer Pre-release Update 3).
Release date: 14 June 2005. The following is a non-exhaustive list of the features of update #3:
AmigaOS 4.0 (Developer Pre-release Update 4).
The most prominent features of the fourth AmigaOS 4.0 Developer Pre-release Update were the return of the screen dragging ability and the Petunia just-in-time 68k emulator.
Release date: 8 February 2006.
The new features in this pre-release include:
AmigaOS 4.0 (The Final Update).
On 24 December 2006, "The Final Update" was released. It came as an ISO image (≈45 MB) and had to be burned onto a CD. The CD is bootable and may be used as a standalone installation CD.
AmigaOS 4.0 Final Update introduced a new memory system based on a slab allocator.
Features of AmigaOS 4.0, among others:
AmigaOS 4.0 (July 2007 Update).
Release date: 18 July 2007.
Improvements of AmigaOS 4.0 July 2007 Update are:
AmigaOS 4.0 for Classic Amiga (with PPC accelerator card).
AmigaOS 4.0 for Amiga 1200, Amiga 3000(T) and Amiga 4000(T) series of computers equipped with Phase5 PowerUP PowerPC accelerator cards was put on sale in November 2007. The feature set was equal to the July 2007 update with drivers for Amiga expansion cards and devices and some minor improvements (e.g. AmigaInput).
AmigaOS 4.0 February 2008 update for CyberStormPPC and BlizzardPPC.
Update of AmigaOS 4.0 for classic Amiga computers addressed some issues and compatibility problems.
Release date: 23 February 2008.
4.1 versions.
AmigaOS 4.1 was presented to public July 11, 2008, and was put on sale for September 2008.
This is a new version and not only a simple update as it features, among others:
AmigaOS 4.1.
AmigaOS 4.1 was presented to the public on 11 July 2008, and was put on sale in September 2008.
This is a new version and not just a simple update as it features, among others:
AmigaOS 4.1 Quick Fix.
On 21 June 2009, Hyperion Entertainment announced the immediate availability of a "Quick Fix" package for AmigaOne, SAM/SAM Flex and Pegasos II.
Features include:
AmigaOS 4.1 Update 1.
On 14 January 2010, Hyperion Entertainment announced the immediate availability of AmigaOS 4.1 Update 1, the first full update to AmigaOS 4.1. Its features include upgrades to the following:
AmigaOS 4.1 Update 2.
On 30 April 2010, Hyperion Entertainment announced the immediate availability of Update 2 for AmigaOS 4.1 for AmigaOne, SAM440EP and Pegasos II for registered users.
Features:
On 17 May 2011, AmigaOS 4.1 for Commodore Amigas with PowerUP accelerators was released.
AmigaOS 4.1 Update 3.
On August 29, 2011 Hyperion Entertainment made available 
Update 3 for AmigaOS 4.1 for AmigaOne, SAM440EP, SAM 460, Classic Amigas with PPC cards and Pegasos II for registered users
Final bugfixes and updates for AmigaOS 4.1, new features are reserved for OS 4.2
AmigaOS 4.1 Update 4.
On December 22, 2011, Hyperion Entertainment released a minor update to correct many bugfixes from the third update of AmigaOS 4.1 and introduces something new.
AmigaOS 4.1 Update 5.
Update 5 was first public release for AmigaOne X1000 on 28 January 2012. Later on 16 August 2012 the Update 5 was released for the other platforms.
AmigaOS 4.1 Update 6.
Update 6 was released on November 30, 2012. It was a rather unusual update in that regard that it included no bug fixes (except new IDE, Xena, and Kicklayout files for AmigaOne X1000). The update consisted mainly of a new and more efficient way of delivering bug fixes. A new "Update software..." menu item on Workbench will launch AmiUpdate which handles all future AmigaOS 4 software updates.
AmigaOS 4.1 Final Edition.
AmigaOS 4.1 Final Edition was released on 18 December 2014, New functionality in AmigaOS 4.1 Final Edition includes: