“Open Educational Resources are teaching, learning, and research resources that reside in the public domain or have been released under an intellectual property license that permits their free use and repurposing by others. OER include full courses, course materials, modules, textbooks, streaming videos, tests, software, and any other tools, materials, or techniques used to support access to knowledge.”
– William and Flora Hewlett Foundation
"Open Educational Resources are teaching and learning materials that you may freely use and reuse at no cost... OER often have a Creative Commons or GNU license to let you know how the material may be used, reused, adapted, and shared."
-- OER Commons
"Open Educational Resources (OERs) are any type of educational materials that are in the public domain or introduced with an open license. The nature of these open materials means that anyone can legally and freely copy, use, adapt and re-share them. OERs range from textbooks to curricula, syllabi, lecture notes, assignments, tests, projects, audio, video and animation."
-- UNESCO
"Open Education encompasses resources, tools, and practices that employ a framework of open sharing to improve educational access and effectiveness worldwide. Open Education combines the traditions of knowledge sharing and creation with 21st century technology to create a vast pool of openly shared educational resources, while harnessing today’s collaborative spirit to develop educational approaches that are more responsive to learner’s needs."
-- Open Education Week
"Open Education encompasses resources, tools, and practices that are free of legal, financial and technical barriers and can be fully used, shared and adapted in the digital environment. Open Education maximizes the power of the Internet to make education more affordable, accessible, and effective."
-- SPARC
"Open Education is a philosophy about the way people should produce, share, and build on knowledge. Proponents of Open Education believe everyone in the world should have access to high-quality education experiences and resources, and they work to eliminate barriers to this goal. Such barriers might include high monetary costs, outdated or obsolete materials, and legal mechanism that prevent collaboration among scholars and educators."
-- OpenSource.com