Microsoft has used a keyboard-based task switching method, enabled by holding down the ALT key and repeatedly hitting TAB (commonly referred to as ALT + TAB), since the early days of Windows. This functionality has been updated significantly in Windows Vista for the first time in over a decade.
Secret: In the earliest Windows versions, ALT + TAB was referred to internally at Microsoft as "cool switch".
In Windows 3.x, ALT + TAB was usable, but it was sometimes confusing because it wasn't always clear which open window would appear next. In Windows 95, Microsoft improved this functionality to display the icon of each open window as you tabbed through the list of running tasks. This made it easier to find the correct window, even if you had several open windows.
Flash forward a decade and users are multitasking more than ever before. Since Windows 95, Microsoft made few attempts at improving the keyboard-based task switching functionality in various Windows versions and add-ons. One notable exception was a Windows XP PowerToy called Task Switcher replaced the normal ALT + TAB functionality with a new switcher pane that featured thumbnails of each running application (Figure). It was a good idea, but the performance was horrible, and of course few users knew it even existed.
Windows Flip
In Windows Vista, ALT + TAB has been renamed to Windows Flip and completely overhauled, assuming you're running Aero Glass. Likewise, a new task switching keyboard combination, called Flip 3D, provides a more graphical way of switching between running tasks. This, too, works only with Aero Glass.
Windows Flip now behaves the way XP's Task Switcher PowerToy did, providing thumbnails of each open window as you tab through the list. The window is nicely laid out. At the top is the name of the current document, if applicable, followed by the application name. Below that is a list of thumbnail representations of the open windows with the currently selected window highlighted. And Microsoft overcame the performance issues that dogged Task Switcher: Thanks to architectural improvements in Windows Vista, which was designed to take advantage of your graphic card's GPU, the thumbnails you see in Windows Flip are rendered almost instantaneously. Here's an example of how Windows Flip looks in Windows Vista.
You may be wondering what Windows Flip looks like in Aero Basic. Here it is:
As you can see, without any glass effects, Windows Flip provides a basic look and feel that is reminiscent of how this feature worked in Windows XP.
Windows Flip 3D
Flip 3D is new and unique to Windows Vista and augments (and will likely eventually replace) Windows Flip. You can access Flip 3D by using the Windows Key + TAB keyboard combination instead of ALT + TAB. (The Windows Key is typically next to ALT on a PC keyboard.) Flip 3D works just like Windows Flip except that the thumbnails representing each window are "live" (that is, if there is any movement like a playing movie, you'll see it behaving normally in this view), much larger than they are in Windows Flip, and they're angled in a stack for an attractive view. Here's what it looks like.
Tip: While in the Flip 3D environment, you can quickly scroll through the list of open windows using your mouse's scroll wheel. (This doesn't work in Windows Flip.) You can also use the keyboard's arrow keys to move through the stack of windows. Simply let go of the Windows Key to exit Flip 3D and select the window that is visually on top of the others in the window stack.
Tip: One interesting feature of Flip 3D (and Windows Flip) in Vista is that the Windows Desktop now shows up as one of the running tasks. So now you can jump directly to the desktop as well, which is handy.
Secret: Mac fanatics claim that Flip 3D is a rip-off of a Mac OS X feature called Expos?. This is untrue: Flip 3D is simply a more graphical version of Windows Flip (i.e. a task switching keyboard shortcut), and it does not include the more advanced features found in Expos?.