Coppermine Photo Gallery
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Coppermine Photo Gallery is a photo-gallery web application with multimedia capabilities. It requires PHP, MySQL, and ImageMagick or the GD Graphics Library, and works with most web server software such as Apache.
Coppermine Photo Gallery has interfaces with many popular software packages, including e107, Invision Power Board, Joomla!, Mambo, phpBB, PostNuke, PunBB, Simple Machines Forum, vBulletin, Woltlab Burning Board, and YaBB SE.
Coppermine is open-source software and is licensed under the GNU General Public License.  However, according to the project FAQ, users are required to have a "Powered by Coppermine" link to the project's web site, and further, to not ask questions on removing the link on the Coppermine support forms. . The compatibility of this requirement with the GPL was discussed in the Coppermine support forum in 2003–2004. The Coppermine team asserts that the "Powered by Coppermine" is legally a copyright notice, which is permitted by the GPL.