Command-Option-Escape

Command-Option-Escape

The key combination in the Mac that enables a user to terminate an unresponsive application. When all three keys are pressed at the same time, the Force Quit utility is launched, which displays all open applications. Like Ctrl-Alt-Del, which brings up Task Manager in Windows, all three keys must be pressed at the same time. See Ctrl-Alt-Del.

A Force Quit Dialog
When a Mac program will not end normally, Force Quit may be an option without having to shut down the computer.