This is an interesting trick that I noticed if you are running KWin: you can very easily forcefully quit a program. Press Ctrl + Alt + Esc, and the cursor is replaced by a skull. Then click the program you want to kill, and it is gone immediately. If you accidentally pressed the shortcut and you don’t want to kill any program, just click on the right mouse button to dismiss the function.
You may have noticed on some pages of this site that I license quite some things under CC0. For example, the Blob font and some programs for graphics calculators. That basically means that everyone can do whatever they like with it: you are allowed to use it, modify it, sell it, remove my name from it and say you made it (although that would be kind of rude), and so on. In this article I want to explain why I do this.