Wikipedia
Piwigo
Piwigo is photo gallery software for the web, built by an active community of users and developers. Freely available extensions make Piwigo easily customizable. It is notable as a system with many features.
Piwigo is a web-based system that is free and open-source, unlike Flickr or Picasa. This approach is reinforced repeatedly. It is licensed under the GPL. It is written in PHP and requires a MySQL database. It can be installed on your own server.