GTK based tool to make annotations on screen with multiple pointers

 Gromit-MPX enables you to make annotations on your screen using
 multiple pointing devices at once.
 .
 This is especially useful when making presentations, to highlight
 things or point out things of interest.
 .
 Gromit-MPX is XInput-Aware, so if you have a graphic tablet you can
 draw lines with different strength, color, erase things, etc.