Wikimedia Commons

Wikimedia Commons is a repository of free images and other media. Many hosting services MediaWiki allow for usage of images and media in articles by entering the file name as if the file was uploaded to the local server.

Related services

 * InstantCommons, a feature of MediaWiki to allow the usage of any uploaded media file from the Wikimedia Commons in any MediaWiki installation world-wide.
 * Wikimedia Apps/Commons, a Wikimedia Commons mobile app that allows users to upload photos directly from their mobile phone into Commons