ImageMagick and GD are two of the most frequently used graphic software libraries out there. They make the dynamic creation and editing of images and graphs on a site doable, so they should be available on a server if you host your websites on it and you would want to have something different from static images with fixed dimensions. If ImageMagick and GD are installed, you'll be able to edit any image in a variety of ways - create thumbnails, change the colors, flip it, blur it, and so forth. However, these changes are possible if the script app that you employ on your website allows you to perform such things. The 2 libraries can be used with numerous website development languages - PHP, Python, Perl, and so forth., and support over one hundred frequently used image formats which you shall be able to work with - PNG, PSD, JPEG, TIFF, GIF and many more.