Wikimedia Commons is a “media file repository” of public domain and freely-licensed educational media content, including images, sounds and video clips. Launched on 7 September 2004 by the Wikimedia Foundation, Wikimedia Commons uses the “wiki-technology” that is the same technology used in Wikipedia. Wikmedia Commons also aggregates files from other projects, including Wikipedia, Wikibooks, Wikivoyage, Wikispecies, Wikisource, and Wikinews. As of October 2015, there are more than 28.7 million files in more than 120,000 collections. Users can conduct a keyword search or browse the content by topic, type, author, location, license and source.
Driven by the LOC Prints & Photographs Division, PPOC contains catalog records and digital images from their holdings. These includes photographs, fine and popular prints and drawings, posters, and architectural and engineering drawings.