They focus on command-line stuff but the graphical stuff is pronounced in various ways as well. For instance, I'm not sure where I got it from, but The X Window

They focus on command-line stuff but the graphical stuff is pronounced in various ways as well. For instance, I'm not sure where I got it from, but The X Window System is either "X" or "The X Window System", but not "X Windows". There must be other "rules".