Tormach is a company that makes on of the most prominent CAM software packages around, Mach3.
CAM stands for Computer Aided Manufacturing. The CAM software is what sends the commands to a CNC (Computer Numerical Control) machine.
Tormach has built a milling machine attachment and a software package. At the end of the attachment is a microscope USB camera.
The CNC machine (commanded by the CAM software (Mach3)) moves the camera around over a part that you want scanned. While commanding the camera to take a series of pictures which are then stitched together and entered into another plugin that helps you to draw that part in your CAD software with a large amount of accuracy. Build Log claims accuracy down to a few thousands.
This is reverse engineering and copying to the N-th level.