Coppermine is free software which you can download and install on your webspace. Using PHP and MySQL as well as GD or ImageMagick Coppermine gallery is a powerful platform for online galleries and images sharing. Coppermine supports template change, user management, private galleries, automatic thumbnail creation, film strip, e-card feature and a template system for easy customization to match the rest of a site.
By categorizing the images into albums and categories you can achieve strict and flexible organization of your images as well as provide different permissions to your users to view only the resources that meet their privileges.
As one of the most popular gallery applications Coppermine gallery has gathered a large community which result in a great number of different plugins, modules and templates.