To force quit an app in OS X Lion, you can use the Command+Option+Escape shortcut and quickly bring up the active apps window with options to force quit them. Apps can also be forced to quit individually from the right-click menu of an app’s icon in the Dock. The shortcoming of all these options, however, is that only apps that are actively running in the Dock can be quit. There are many apps that run from the Menu Bar, and processes that run in the background, which you can’t stop using this approach. Ctrl Alt Delete is a free Mac app that extends the options you get and makes it easier to quit any app or process. It is mapped to work with the Control+Alt+Delete key combination, which is the Windows shortcut for bringing up system options including the Task Manager (the Windows equivalent to Activity Monitor). Since there is no Alt key in Mac, the combination you will use is Control+Option+Delete. The app not only quits apps, but can also hide them and force your system to log off, sleep, restart or shutdown.
Ctrl Alt Delete adds an icon to the menu bar which resembles the line on an ECG monitor. You can open the app and its preferences by clicking this icon, or just by hitting the keyboard shortcut. It lists all apps that are running in a panel on the left. You can select any or multiple apps by holding down the Command key and clicking the ones you want to quit. Buttons for hiding, quitting or force quitting apps are located on the right just below the details of the selected app. Another four buttons let you log off, sleep, restart or shut down your system.
A cog wheel button located at the bottom left of this window opens a menu where you can access the app’s settings. From the settings window, you have options to choose the delay before the app executes a log off, sleep, restart or shut down command. The maximum delay that you can set is for 1 minute (60 seconds). You may also edit the shortcut for activating the app when it is running in the Menu Bar, set Ctrl Alt Delete to start at login and keep the window floating above all other apps’ windows.
To close these windows, just click the icon in the Menu Bar again. When the window is open, the icon turns blue, and greys out when it is closed. The app is excellent not just to view all currently active apps and processes, but also for easily quitting them.