Connexions - educational content that are targeted at supporting education, research and related scholarly activities.
Curriki – makes world-class learning materials freely available to educators, students, and parents around the world.
Directory of Open Access Journals The aim of the DOAJ is to increase the visibility and ease of use of open access scientific and scholarly journals, thereby promoting their increased usage and impact.
Flat World Knowledge - This is a college textbook publisher whose books are published under an open license.
Maricopa Learning Exchange- The Maricopa Learning eXchange (MLX) is an electronic warehouse of ideas, examples, and resources (represented as "packages") that support student learning at the Maricopa Community Colleges.
MERLOT - Multimedia Educational Resources for Learning and Online Teaching (MERLOT) is a project of California State University and offers peer reviewed online teaching and learning materials.
OpenStax College - OpenStax College offers students free textbooks that meet scope and sequence requirements for most courses. These are peer-reviewed texts written by professional content developers
Public Domain Images Public domain images, royalty free stock photos, copyright friendly free images. Not copyrighted, no rights reserved.
Library of Congress Prints & Photographs Online Images from the Library of Congress, now in the public domain.
National Gallery of Art With the launch of NGA Images, the National Gallery of Art implements an open access policy for digital images of works of art that the Gallery believes to be in the public domain.
Digital Public Library of America The Digital Public Library of America brings together the riches of America's libraries, archives, and museums, and makes them freely available to the world.