Lightbox Image Viewer is a Scripts software developed by Lokesh Dhakar. After our trial and test, the software is proved to be official, secure and free. Here is the official description for Lightbox Image Viewer:

Edit by Marydown: Lightbox is a simple, unobtrusive script used to Overlay images on the current PaGE. It's a snap to setup and works on all Modern browsers.

What's New in Version 2
Image Sets: group related images and navigate through them with ease
Visual Effects: fancy pants transitions
Backwards Compatibility: yes!