CSS Popup Image Viewer is a Scripts software developed by Dynamic Drive. After our trial and test, the software is proved to be official, secure and free. Here is the official description for CSS Popup Image Viewer:

Enable arbitrary links or image thumbnails to pop up an enlarged (different) image onMouseover by using this CSS code. With the help of CSS's ":hover" Pseudo class, combined with relative and absolute positioning, the enlarged images are simply included on the PaGE as normal HTML, "popping" up on demand. CSS is behaving more and more like scripting!