ImageMagick and GD are 2 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 need to be set up on a web server if you host your websites on it and you would like to have something different from static images with fixed dimensions. If ImageMagick and GD are set up, you'll be able to edit any image in various ways - create thumbnails, change the colors, flip it, blur it, etcetera. Naturally, these tweaks are doable if the script app that you use on your internet site allows you to carry out such things. The two libraries can be used with different programming languages - PHP, Python, Perl, and so on., and support over a hundred widely used image formats which you will be able to work with - PNG, PSD, JPEG, TIFF, GIF and many others.