Openly Available Sources Integrated Search (OASIS) is a search tool that aims to make the discovery of open content easier.
OASIS currently searches open content from 117 different sources and contains 440,269 records.
"Open Educational Resources (OER) 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 re-purposing by others.
They include full courses, course materials, modules, textbooks, streaming videos, tests, software, and any other tools, materials, or techniques used to support access to knowledge." - Hewlett Foundation
The terms "open content" and "open educational resources" describe any copyrightable work (traditionally excluding software, which is described by other terms like "open source") that is licensed in a manner that provides users with free and perpetual permission to engage in the 5R activities:
This material was created by David Wiley and published freely under a Creative Commons Attribution 4.0 license at opencontent.org .
OER are typically licensed using Creative Commons licensing. For information about Creative Commons, see the graphic below or visit https://creativecommons.org/.
What is Creative Commons? - Full-text PDF of the image above from Creative Commons.
The Library, Technological University of the Shannon: Midwest