Keith's Image Stacker for Mac

From Keith Wiley:

Keith's Image Stacker is an image processing program that is oriented primarily toward astrophotography. What Keith's Image Stacker provides, more than anything else, is a workspace in which to align many similar images (say from a quicktime movie of the moon, a planet, or a series of long exposures of a deep-sky object, taken through a telescope with a webcam) and then to produce a stack of the images, which consists of a single image that comprises the average of the individually stacked images. Stacking images is a well-established method for increasing the signal-to-noise ratio in a series of similar images. True "information" will shine through the stack, while random noise will drop out.