Windows Shell

In computing, Windows Shell is the most visible aspect of the Microsoft Windows line of operating systems. The shell is the container inside of which the entire user interface is presented, including the taskbar, the Desktop, Windows Explorer, as well as many of the dialog boxes and interface controls, but also describes the past shells, like MS-DOS Executive and Program Manager.

The default Windows shell is called Explorer (confusingly, the same as the MS file browser) — this is the program that determines the look of your desktop, i.e. it creates the task bar, system tray, start menu etc.

Windows 1 and 2 - Early UI
Just after the PC hit the market (August 1981), a project named "Interface Manager" started. It was renamed to "Windows" because the programmers talked very much about the zones called "windows" on the screen. Rowland Hanson, the head of marketing at Microsoft, convinced the company that the name Windows would be a more appealing name to consumers. The first Windows pre-version was presented in November 1983. It used Word for DOS-like menus at the bottom of the screen. The 1.0 version (it was numbered 1.01; it is rumored that version 1.00 was actually released but quickly pulled due to a severe flaw), released in November 1985, used pull-down menus like the early Macintosh System 1.x (Microsoft actually licensed GUI elements from Apple). The shell was a file manager (not a program manager) called "MS-DOS Executive". Applications could be launched from the MS-DOS Executive which minimized itself. The minimizing (called "iconing") was done by transforming the windows into an icon which was placed at the bottom of the screen, in a special minimized windows zone. The maximizing (called "zooming") could extend the window over the minimized windows zone. Windows could not be overlapped, but they were instead "tiled". As a result, two windows could not be "zoomed" at the same time.

Windows 2.0 was an interface-based release. The new window controls were introduced with this release, with the new "minimize" and "maximize" terminology. Windows could be overlapped and the minimized window icons could be moved freely on the desktop.

OS/2 1.x
As of version 1.1, launched in 1988, the new OS/2 operating system from IBM introduced a new GUI, called the Presentation Manager. The default shell (a program) was a program manager (not a file manager like in Windows 1.x and 2.x) called "Start Programs". Versions 1.2 and 1.3 renamed "Start Programs" to "Desktop Manager", added 16-colour icons support and many more.

Windows 3.x, NT 3.x - The First Revolution
Windows 3.0, introduced in May 1990, inherited the OS/2 GUI. The new "Program Manager" was a simple "front end" where the "groups" and icons had no relation to the actual file system. A background could be put on the desktop, and the window controls were redesigned. The buttons were all in 3-D appearance (the windows weren't). As a result, the Windows 3.0 operating environment was a success. Later versions of Windows 3.x introduced Screen Savers.

The new operating system from Microsoft, "Windows NT", featured the same GUI in the first version (3.1), like Windows 3.1x.

Windows 95C, 98 - "Nashville"
The growing popularity of the World Wide Web forced Microsoft to release its own browser, dubbed "Internet Explorer" which was based on technology licensed from Spyglass. In early 1996, Netscape announced that the next release of its browser, Netscape, would completely integrate with Windows and add a new shell, codenamed "Constellation". Microsoft started working on a similar Internet Explorer release, codenamed "Nashville". Internet Explorer 4.0 was redesigned and resulted in two products: the standalone IE4 which replaced the Windows shell with a new "Active Desktop" shell and the future Windows releases, like Windows 95C and Windows 98, which integrated Internet Explorer and Active Desktop in the shell.

Georgia, Neptune and Tiger
Windows 2000 (NT 5.0) also integrated Internet Explorer into the shell and added some new capabilities, such as extended Start Menus and some eye candy. This interface was codenamed "Georgia". Windows Me also added these features. In the meantime, some new Windows versions were planned, "Neptune" and "Odyssey".

Neptune and Odyssey were cancelled in January 2000 and replaced with "Whistler". But before that, an early alpha release of "Neptune" appeared. It featured Activity Centers, which were also cancelled along with "Neptune" and "Odyssey".

"Tiger" was a short-lived idea for continuing the DOS/9x platform. Some fake screenshots were leaked, featuring a new task-based, 2000 white-style interface.

Odyssey, Whistler - The skinning engine
"Odyssey" was designed to have a skinning engine similar to Stardock's WindowBlinds. It was later incorporated into "Whistler" (the "skin" name was changed to "visual style"). Two visual styles were developed: one "Professional" and one "Home". Early builds of "Whistler" (later named Windows XP) shipped only with the "Professional" visual style (later renamed to Watercolor), which was developed initially for Odyssey, but later Microsoft polls showed that consumers were interested in the "Home" visual style, which later replaced Professional/Watercolor.

XP, Server 2003 - "Luna", "Royale"
The "home" skin became known as "Luna", and this refined version featured other UI elements, such as a reworked Start Menu and Control Panel. It was shipped with Windows XP. It received an update with Windows XP Media Center Edition 2005, called "Royale". Windows Server 2003 featured the same Luna UI.

Vista - Aero

 * See also: Windows Aero

The Aero UI was introduced with Longhorn build 5048 and was developed along with the Vista builds, Beta 1 and the CTPs.