Adobe Photoshop is a versatile program that allows you to manipulate images. Paired with the free downloadable plugin, FITS Liberator, Photoshop can readily open and manipulate FITS files straight from the telescope.
More information about Photoshop can be found at: www.adobe.com/products/photoshop/family/
More information about FITS Liberator can be found at: www.spacetelescope.org/projects/fits_liberator/
Instructions on how to use Photoshop Elements 5.0 with FITS Liberator (PDF)
