Wikimedia Commons is an online repository of free-use images, sound and other media files. It is a project of the Wikimedia Foundation. It's built on MediaWiki, so it can also be accessed through the MediaWiki API.
Wikimedia Commons is an online media file repository of free-use images, sound and video clips. It acts as a common repository for the various projects of the Wikimedia Foundation.
It's built on mediawiki, so it can also be accessed through the mediawiki-api. Unlike media files uploaded to other projects, files uploaded to Wikimedia Commons can be embedded on pages of all Wikimedia projects without the need to separately upload them there.
Unlike traditional media repositories, Wikimedia Commons is free. Everyone is allowed to copy, use and modify any files freely as long as they follow the terms specified by the author; this often means crediting the source and author(s) appropriately and releasing copies/improvements under the same freedom to others. The license conditions of each individual media file can be found on their description page. The Wikimedia Commons database itself and the texts in it are licensed under the Creative Commons Attribution/Share-Alike License.