ImageMagick and GD are 2 of the most popular graphic software libraries on the market. They make the dynamic creation and editing of images and graphs on an internet site feasible, so they ought to be available on a server if you host your internet sites on it and you would like to have something different from static images with fixed dimensions. If ImageMagick and GD are present, you shall be able to edit any image in many ways - create thumbnails, change the colors, flip it, blur it, etc. Needless to say, these tweaks are feasible if the script application which you employ on your internet site enables you to do such things. The two libraries could be used with many website development languages - PHP, Python, Perl, etcetera., and support more than one hundred commonly used image formats that you will be able to work with - PNG, PSD, JPEG, TIFF, GIF and many more.