FlatGallery is a simple image gallery that does not require a database backend. Users simply add images to a directory, and the system recognises this and produce thumbnails that are cached for later use. Producing thumbnails only when images are added lessens the strain on servers that produce thumbnails "on the fly" for every image, every time the page is refreshed. It also deletes thumbnails when the image is removed from the image directory. Nearly all aspects of the program are customizable, including the number of images per page, thumbnail size, and what to display.