PageRank 4 Based on telescope design program MODAS, can design and analyze one mirror and classical two or three mirror telescopes, one mirror catadioptric systems, two mirror catadioptric systems, doublets and triplets, and includes applets.
PageRank 5 Freeware, Version 3.0, that generates star-testing images to show the effects of distortions influencing the quality of a telescope's performance.