System Activity

See your running processes listed

In KDE SC 4.3, this can only be accessed by the keyboard shortcut Ctrl-Esc. A menu entry may follow.

This is particularly useful when you have a misbehaving window, that refuses to close by normal methods. Simply highlight the process, then hit the Kill button.

You can, of course, choose between seeing All Processes, User-owned Processes, System Processes and Programmes Only. If you select All Processes, Tree, you can see whether anything else might be affected by killing your problem window.