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.
Founded by a startup based in Switzerland, PLiXS is a database of free high resolution images. As of August 2015, there are close to 3,400 images, contributed by photographers around the world. Users can search or filter their search by photo filters and categories.
Skitterphoto provides photographs that are taken by three photographers based in Groningen, The Netherlands. Since the platform launched in 2014, a photo is uploaded every single day. Users can search or browse by categories.
The Biodiversity Heritage Library (BHL) is “a consortium of natural history and botanical libraries that cooperate to digitize the legacy literature of biodiversity held in their collections and to make that literature available for open access and responsible use as a part of a global ‘biodiversity commons'”. Started in 2011, the staff of BHL began to upload illustrations from books in their collections. These illustrations were created over the past 500 years. To date, more than 98,000 of natural history and botanical illustrations have been uploaded to their Flickr account.
The National Geographic Society is one of the largest scientific institutions in the world, focusing on geography, archaeology, natural science, conversation and the study of world culture and history. They offer stunning photographs, which can be a good source of images in these areas for educational and personal purposes.
Compiled by Swiss UI designer, Vilem Ries, Albumarium offers high-resolution photographs, organised in different albums. Photographs on this site are contributed by users on Creative Common licenses.
Developed by Michael Connors in 1996, MorgueFile is an online community for photographers and remains as a popular image source for creatives. It is currently managed together by Michael and his brother, Kevin Connors, and Johannes Seemann. This platform contains photographs “freely contributed by many artists to be used in creative projects by visitors to the site“.