Killing a non-responsive program in Linux.

Most know ctrl+alt+delete for Windows will open the task manger.

In Linux it's still pretty easy and this should work with every flavor of Linux.
Xubuntu, Ubuntu, Fedora, Mint, Red Hat...

Open your favorite Terminal Window.
In the command line type ps -A 
Hit the enter key that will show you all the things running on your system.
Then there are two ways to shut it down.
Look for it's ID "4444"
In the command line type killall 4444
Hit the enter key.

If that doesn't work use this one. I like this on.
python3 is the name of the running program so it will be what ever you're trying to close.
gedit, firefox, slimjet...
In the command line type killall python3 (The name of whatever program you are trying to shut down)
Hit enter and it will close