DxO ViewPoint is a photo editing software package that allows you to correct keystoning and deformed proportions along the edges of your photos easily. It works especially well with photos taken with a wide-angle lens, which usually has distorted edges in photos. ViewPoint also provides the Loupe tool so you can precisely place your anchor points so that slider settings are accurate at all zoom levels to help you achieve the best possible corrections.
Included in the CLL are: