What does xkill mean and do?

I found xkill on dashboard and my pointer turned into an "x" sign on clicking it. It doesn't change back when I press Esc.

What does this "x" sign stand for and what does it do?

Solution 1:

xkill is a utility used for force-quitting GUI apps. It is handy when some app isn't responding or is causing your system to work abnormally.

NAME

xkill - kill a client by its X resource

DESCRIPTION

Xkill is a utility for forcing the X server to close connections to clients. This program is very dangerous, but is useful for aborting programs that have displayed undesired windows on a user's screen. If no resource identifier is given with -id, xkill will display a special cursor as a prompt for the user to select a window to be killed. If a pointer button is pressed over a non-root window, the server will close its connection to the client that created the window.

To use it quickly you can use Alt+F2 and enter xkill and hit Enter. Alternatively, you can also type the same in Terminal. You can also define a keyboard shortcut in Settings → Devices → Keyboard to use xkill.

Your cursor will turn into cross sign and forcefully terminate (finishes the game (what I think) of) the app.