Epic Pen - A windows tool for drawing over your desktop and applications
gInk - An on-screen on-screen annotation software for Windows.
Pylote - To draw on the screen and to handle the instruments of geometry there.
ZoomIt - Presentation utility for zooming and drawing on the screen.
Gromit-MPX - Create annotations by directly drawing on your screen.
FrontSketch - Highlight, annotate, draw, capture, write on your computer screen during run-time