Keith's Image Stacker is an image processing program that is oriented primarily toward astrophotography. See my astrophotography webpage for information about my personal venture into that hobby. 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 Jupiter taken through a telescope with a webcam) and then to produce a stack of the images, which consists of a single image that comprises either the sum, or the average, or some value in between 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.