ImageMagick and GD are two of the most widely used graphic software libraries available on the market. They make the dynamic creation and editing of images and graphs on an internet site possible, so they should be available on a server if you host your sites on it and you prefer to have something different than static images with fixed dimensions. If ImageMagick and GD are present, you'll be able to edit any image in many ways - generate thumbnails, change the colors, flip it, blur it, and so on. Naturally, these tweaks are feasible if the script app that you use on your internet site allows you to perform such things. The 2 libraries can be used with various web development languages - PHP, Python, Perl, and so forth., and support more than 100 widely used image formats which you shall be able to work with - PNG, PSD, JPEG, TIFF, GIF and others.