Pixabay is a photo community that provides images on public domain. The site contains curated images contributed by photographers around the world. As of September 2015, there are more than 470,000 photographs, vectors and illustrations. Users can search by keywords or browse by various categories.
Since 2013, British Library released more than 1 million images to Flickr Commons. The images were obtained from the Library’s digitised collection of 65,000 books of the 17th, 18th and 19th century. The release of these images indicates the Library’s desire “to improve knowledge of and about them, to enable novel and unexpected ways of using them, and to begin working with researchers to explore and interpret large scale digital collections”. The images are arranged by different themes, such as book covers, illustrated letters, maps, flora and children book illustrations.
The Museum of Fine Arts Boston is one of the most comprehensive museums in the world. From Ancient Egypt to contemporary art, the museum has nearly 450,000 works of art in its holdings. Its digital collection allows users to search and refine the results by collection type and classification.
As one of the largest museums in the world, the Metropolitan Museum (MET) provides access to more than 400,000 high-resolution digital images of public domain works across different periods and geographic locations. Such works can be downloaded directly from the Museum’s website for non-commercial use—including in scholarly publications in any media—without permission from the Museum and without a fee.