Showkeys is a simple program to display keys being pressed on the screen.

It is useful while making presentations and screencasts. The audience will be
able to see the keys being pressed.

It is similar to key-mon. Key-mon has more features than showkeys. The
advantages of showkeys are

1. Doesn't use GTK/GNOME.
2. Uses libXosd to display keys directly onto the screen.
3. No floating windows that always need to be on top. This is very useful if
   you're using a tiling WM like Xmonad.
4. Keystroke history. key-mon has this but doesn't show modifiers. showkeys
   does this using an Emacs style key notation.