Witch is a System Preferences utility for Mac OS X, allowing you to customize the process of cycling between windows, which is traditionally accomplished with "Command + Tab" ("Alt + Tab" on Windows).

The traditional approach has a few drawbacks, specifically on Mac OS X:

1. You are limited to cycling only between open applications, as opposed to open windows.
2. You cannot cycle to minimized windows or applications (It will take you to the app, but the physical window remains minimized).
3. You can't perform any other actions on cycled windows, such as close, maximize, etc.

Witch corrects all of these problems, and allows more fine-tuned control over open windows.

I've tested Witch on Mac OS X Tiger. I haven't heard of any significant changes to the "Command + Tab" feature of Leopard, so I'm assuming the same rules apply.

Using Witch

Witch installs as a system preferences extension. To activate Witch, you supply a keyboard combination (such as "Ctrl + Tab").

Witch's level of customization is almost scary, hence the name Witch. (I just came up with that on my own, by the way.)

You can set triggers for various types of "window cycling."

Additional actions are allowed to provide more control over each cycled window.

You can also customize the appearance, and provide further fine-tuned control.

What I like

I like being able to customize the appearance of the window. Right now I am going with a solid black background, and green hover color.

It's also nice to have a "Cancel" option included, because often I'll start cycling through windows, and decide I don't want to change windows at that moment. The "Cancel" option immediately brings you back the window you were on.

You can also tell Witch to start cycling with the current window, and not the next window. This allows you to immediately change your mind without jumping to a new window (and then having to cycle back). However, some may not like this, because then if you truly wish to jump back and forth between two windows, you'd have to tab twice.

All these features really make me wonder just how much control users actually want when cycling windows.

Room for improvement

One thing I wanted to do was to re-map "Command + Tab" to use Witch, but it doesn't seem to be possible. Instead I opted for "Ctrl + Tab" to activate Witch, which is not as natural, and during my typical work day haste, I forget to use "Ctrl + Tab" and naturally use "Command + Tab."

Be careful using "Option + Tab" if you use Remote Desktop software for connecting to Windows PC's. "Option + Tab" on OS X is identical to "Alt + Tab" on Windows, so if you have Witch mapped to "Option + Tab," you won't be able to cycle between applications within Remote Desktop sessions connected to Windows.

Another thing Witch doesn't do is allow you to cycle between open tabs in applications such as Firefox. I understand a tab is not physically another window, but it still would be nice to see all my open Firefox tabs, from within Witch. I could then cycle to any open tab.

Overall

The features in Witch are nothing to scream about (another good one!), but if you're looking for a simple utility to enhance traditional "Command + Tab", Witch may be your answer.