Mac OS X: How to quit an unresponsive application using Force Quit
Summary
Force Quit forces an application to quit. Important: You should only force quit if absolutely necessary. When an application is force quit, any unsaved changes to open documents are not saved.
Consider force quitting only if an application is unresponsive and cannot be quit in a usual manner (such as by choosing Quit from the menu named for the application).
Products Affected
Mac OS X 10.4, Mac OS X 10.5, Mac OS X 10.3, Mac OS X 10.2, Mac OS X 10.1, Mac OS X 10.0
To force quit an application, choose Force Quit from the Apple menu (or press Option-Command-Esc), then choose the unresponsive application in the Force Quit window, and click Force Quit.
Optionally, you may be able to Option-right click the application's icon in the Dock and choose Force Quit from the contextual menu.
Additional Information
If the Finder is unresponsive, you can use Force Quit to quit and relaunch it. Select Finder in the Force Quit Window, then click Relaunch.