CCD Inspector, written by Paul Kanevsky and sold by CCDWare, is software that can analyze astronomical images to determine the degree of focus, collimation, and alignment of the optical system used to take the image. It can be used "live" as a help to collimating the scope, but most often is used after collecting a number of images, to sort them in terms of image quality (so only the best ones are 'stacked' into a final image).

CCDIS can produce a color map of the telescope field - in terms of flatness, tilt, and collimation, as shown below. This is a typical result from my 12" LX200R scope over a 15 arcminute field (ST-4000XCM 17mm camera chip with 7.4 micron pixels). This is very good, having only about 8% curvature, essentially no tilt, and being very well collimated.

Pictured below are two CCDIS runs, with not-so-good results. The image on the left exhibits tilt, and the image on the right severe curvature:

CCDIS can also be used to chart the trend of various parameters, such as star diameter, background noise (i.e., sky brightness), etc. throughout the night. Shown below is a graph of the "seeing" during one night of imaging; this is plotting the average stellar diameter of each image (every image was focused separately). You can see that the seeing is improving during the first dozen images, and then starting to get worse again.