Workbench 2.0, 2.04, 2.05, 2.1
Workbench 2.0 was released in 1990 and introduced a lot of improvements and major advances to the GUI of the overall Amiga operating system. The harsh blue and orange colour scheme was replaced with a much easier on the eye grey and light blue with 3D aspect in the border of the windows. The Workbench was no longer tied to the 640×256 (PAL) or 640×200 (NTSC) display modes, and much of the system was improved with an eye to making future expansion easier. For the first time, a standardised "look and feel" was added. This was done by creating the Amiga Style Guide, and including libraries and software which assisted developers in making conformant software. Technologies included the GUI element creation library gadtools, the software installation scripting language Installer, and the AmigaGuide hypertext help system.
Workbench 2.04 introduced ARexx, a system-wide scripting language. Programmers could add so-called "ARexx ports" to their programs, which allowed them to be controlled from ARexx scripts. Using ARexx, you could make two completely different programs from different vendors work together seamlessly. For example, you could batch-convert a directory of files to thumbnail images with an ARexx-capable image-manipulation program, create and index HTML table of the thumbnails linking to the original images, and display it in a web browser, all from one script. ARexx became very popular, and was widely adopted by programmers.
The AmigaDOS, previously written in BCPL and very difficult to develop for beyond basic file manipulation, was mostly rewritten in C.
Unfortunately, some badly written software – especially games – failed to run with 2.x, and so a lot of people were upset with this update. Most often, the failure occurred because programmers had used directly manipulated private structures maintained by the operating system, rather than using official function calls. Many users circumvented the problem by installing so-called "kickstart switchers", a small circuit board which held both a Kickstart 1.3 and 2.0 chip, with which they could swap between Kickstart versions at the flick of a switch.
2.x shipped with the A500+ (2.04), A600 (2.05), A3000 and A3000T. Workbench 2.1 was the last in this series, and only released as a software update. It included useful features such as CrossDOS, to support working with floppy disks formatted for PCs. Since 2.1 was a software-only release, there was no Kickstart 2.1 ROM.
2.x also introduced PCMCIA card support, for the slot on the A600.
Workbench 2.1 introduced also a standard hypertext markup language for easily building guides for the user or help files, or manuals.It was called Amigaguide. Release 2.1 was also the first Workbench release to feature a system-standard localization system, allowing the user to make an ordered list of preferred languages; when a locale-aware application runs, it asks the operating system to find the catalog (a file containing translations of the application's strings) best matching the user's preferences.
Read more about this topic: Amiga OS Versions