Many PHP based gallery systems currently exist. However, many require setting file permissions as writable for the webserver or a connection to a database. Often it is not possible or practical to do this, especially if you do not need advanced functionality. FreeGallery is designed to fit into the gap this category, simply copy the necessary files to the webserver, no further setup is needed. This allows for very portable gallery systems to be created, and even distributed with a small webserver on image CDs or in .zip/.tar files.
This software is licensed under the CC-GNU GPL.