ImageMagick and GD are two of the most popular graphic software libraries available. They make the dynamic creation and editing of images and graphs on a site doable, so they need to be installed on a server if you host your websites on it and you would want to have something different than static images with fixed dimensions. If ImageMagick and GD are present, you shall be able to edit any image in many different ways - create thumbnails, change the colors, flip it, blur it, and so on. Naturally, these changes are possible if the script app that you employ on your website enables you to do such things. The 2 libraries could be used with numerous programming languages - PHP, Python, Perl, and so forth., and support over 100 frequently used image formats which you'll be able to work with - PNG, PSD, JPEG, TIFF, GIF and more.