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.
Google developed a visual language that “synthesizes the classic principles of good design with the innovation and possibility of technology and science”, which they called “material design”. Google retains a living document of specifications of the material design. As part of the specifications, Google provides a library of system icons, created based on Google’s design principles, for download. Users can search or browse the icons arranged by categories.
From vectors to PSD files, icons and stock photos, Freepik provides resources for graphic and web design. As of August 2015, the site has received more than 440 million downloads. Developed by “a team of designers, developers, professionals of marketing, communication and administration” based in Spain, Freepik offers two types of content: free and exclusive graphic resources by Freepik, and graphic resources belonging to others. Users can search or browse by categories.
Provided by web design agency, IM Creator Ltd., IM Free Collections is “a curated collection of free web design resources”. The images are from various image sources that provided these images on Creative Commons licenses. Users can search or browse by various categories.
Launched in 2010, The Noun Project is an online catalog of downloadable icons and symbols submitted by designers around the world. Users may search for png or editable svg files of the icons.