GalleryCMS is an open source CMS application that is specially built for managing image galleries.
The application does not offer a front-end to the galleries. It enables you to create galleries, add images with ease & generates a XML file which can be used for creating the gallery.

The format of the XML file created can be customized which makes GalleryCMS ideal for using with the Flash & JavaScript galleries around that has no backends.
It is built with the CodeIgniter framework & can be installed very quickly.
Requirements: PHP (GD library enabled), Database (compatible with most)
For every e-commerce website, web application or even a standard website, knowledgebases are very useful systems for helping users to find answers themselves.
68KB is a free knowledgebase application that is built with PHP & MySQL & can be themed to match the look of any website.

It has support for unlimited categories/sub-categories & SEO friendly URLs. Also, features like an "integrated glossary", "popular & new articles" makes browsing much easier.
With the help of an admin interface, it is possible to manage the system easily, view the stats, search logs & more.
68KB is multilingual & built with the CodeIgniter framework.
Requirements: PHP 4.3.2+, MySQL 3.23+
Compatibility: All Major Browsers
dfGallery 2.0, the new version of the popular free Flash image gallery, is totally updated & offers a beautiful experience.
The gallery application has lots of features but still easy to use & have a slick look.

The gallery has integration support with Flickr & Picasa. It can get all Flickr albums under a user with the API key or any Picasa albums via the URL of the album.
dfGallery 2 can display multiple albums that can be switched via the interface. Images can be manually browsed or as a slideshow.
You have the full control over the gallery with an Ajaxed admin panel that supports multiple uploads & built on CodeIgniter.
Other features
- Theming support (change the layout and the presentation of the gallery)
- Skinning support
- Customizable background music
- Fullscreen feature
Click here for a demo of the gallery.
Requirements: PHP