By Prince McLean

Published: 10:00 AM EST

The Dock in Mac OS X is unique in comparison to the user interface of Windows, most Linux distros that emulate the Windows desktop, and previous versions of the Classic Mac OS. Apple has significantly updated the Dock in Mac OS X 10.5 Leopard. Here's a look at what's new and different in our 3-page report.

This report goes to great lengths to follow the origins, history, and maturity of the Dock. For those readers with limited time or who are only interested in what's due in Leopard, you can skip to page 2 of this report.

The Dock's Origins

On the Mac, the Dock first appeared to the public in the beta preview of Mac OS X released in late 2000, which debuted the new Aqua interface. However, the ideas behind the Dock weren't all new. In the 1987, Apple's English dopplegänger, Acorn Computers, shipped its Mac-like RISCOS with a desktop operating system featuring an Iconbar. The strip on the lower edge of the screen displayed icons for drives and running applications. By the early 90s, the RISCOS Iconbar displayed icons for RAM disks, printers, folders, applications and system utilities.



The NeXT Dock

In 1988, Steve Jobs' NeXT began demonstrating the new desktop of NeXTSTEP, which included the new Dock. NeXT's Dock was a series of block icons, each of which could animate and update. Icons in the Dock could represent running applications or apps ready to be launched; the icons of running apps were tagged with an ellipsis to differentiate them (as is the Digital Librarian icon, fourth from the top, in the desktop image below). That made the NeXT Dock more of an application launcher.

Since icons couldn't be resized, the Dock consumed a lot of screen real estate. NeXT also provided no way to drop other placeholders into the Dock, such as files, folders, or open windows. Files and folders could be instead be dropped into the Shelf, a reserved space in File Viewer windows (analogous to Mac Finder windows).

In the screen shot below, the top four icons in the File Viewer window are sitting in the Shelf, while icons of the Dock are positioned along the right and bottom of the screen. NeXT also moved the desktop Mac trash icon into a Dock icon called the Recycler. The dynamic nature of the icons can be seen in the live time and date displayed by the preferences icon (second from top) and the Mail badge indicating new messages (third from top).



Newton's Dock

In the early 90s, Apple introduced the MessagePad running Newton OS, which similarly used a "buttonbar" as a launcher. The Newton's buttonbar demonstrated the significant resources Apple invested in reducing the amount of clicking required to pull up common tasks on the Newton. Other items could be dragged into buttonbar from a collection of extras, similar to the row of action icons on the iPhone's More/Edit/Configure screen within its iPod section.



Dock Substitutes in the Classic Mac OS

The Newton's button bar never made it into the classic Mac OS, then called System 7. Instead, Apple rounded up various shareware tools and incorporated them into the Mac desktop throughout the 90s. Oddly, there was never any way to tell at a glance which apps were actively running on the classic Mac, an obvious need solved by NeXT's Dock years before the Mac OS was even routinely running multiple applications at once.

Instead, the classic Mac OS used an icon in the top right to indicate the currently running app, which would drop down a menu of other running applications. This Application Menu also served as a way to select between running apps. It was not an app launcher however.



Apple added various systems to the Mac OS to provide functions later handled by the Mac OS X Dock:

• In System 7, the Control Panel desk accessory for setting system settings such as screen resolution and audio volume was exposed as the Control Strip (above, lower left), a Dock-like selection of small icons that floated on top of other windows. It did not launch or display applications, and was really intended only for use on PowerBooks.
• Later, Tabbed Windows (above, lower right) allowed users to collapse an open window into a labeled tab on the edge of the screen; selecting the tab would pop it up back to full size.
• Windowshade allowed open windows to be alternatively minimized in place, rolling the window's contents up into their titlebar
• A separate Launcher in Mac OS 8 (below) provided an editable listing of programs grouped by sections.

Windows: No Dock For You

While Microsoft's Windows borrowed heavily from both the Mac and from NeXT, it did not incorporate anything like the NeXT Dock. Instead, it designated a horizontal TaskBar, which creates a rectangular bay for each open window. The obvious flaw of dividing up the horizontal Start Menu bar into rectangles for each open window is the finite space involved. The perpetually cramped TaskBar doesn't make it clear and obvious which apps are running if more than a few are. Individual windows of a single application are also difficult to represent using wide horizontal bars when more than a half dozen windows are open. There is also no way to scale the tiny icons used in the TaskBar.



In 2001, Windows XP tried to address the problem of cramped boxes in the TaskBar -- the inherent result of squeezing multiple, wide bars into a narrow strip -- by grouping together the windows of each app into grouped TaskBar items. Grouped items reveal detail when popped-up into a menu of nearly impossible to read window titles. This only further obscured the individual windows of an app, similar to how the classic Mac OS Application Menu made it clumsy to view the currently running applications.

The Windows TaskBar also does nothing to launch applications; Microsoft added a QuickLaunch bar to do that, which sits between the Start Menu and the TaskBar. After launching an app, QuickLaunch does nothing; it doesn't indicate that the app is actually running, and doesn't relate to that application's windows in any way. Oddly, this most useful interface convention of Windows was downplayed in Windows XP Professional, which turns the QuickLaunch off by default; it requires editing the Start Menu settings to restore.

Microsoft may have backpedaled on QuickLaunch to direct attention toward the fancier Start Menu of Windows XP, which requires navigating deeply nestled submenus to launch a application; it was actually presented as a feature. The main problem with QuickLaunch is that it competes with the TaskBar for the minimal space available; having a few QuickLaunch icons means you have even less room to display TaskBar bays for the currently open windows. Users who only ever open three windows won't see the problem, so XP Home leaves the QuickLaunch bar on. However, anyone who uses their PC to do more than browse the web will find the TaskBar nearly worthless even before cramping it up with a selection of QuickLaunch icons.



This year's Windows Vista did nothing to fix the absurd Start Menu bar aside from making the Start Menu a round logo ball that conveys even less information about how it might be used, and making the bar itself glossy. The scrunched TaskBar bays can now popup a live preview of the Window they relate to (above), but this requires mousing over each TaskBar bay. Imagine if live previews were just sitting there, live, to preview at a glance without any mousing around? That would take you back half a decade to Mac OS X's Dock.

On page 2: Mac OS X: Return of the Dock; The New Dock in Mac OS X Leopard; and Stacks Take Back the Dock