Open Educational Resources (OER) are teaching, learning and research materials in any medium – digital or otherwise – that reside in the public domain or have been released under an open license that permits no-cost access, use, adaptation and redistribution by others with no or limited restrictions. - UNESCO

YouTube Video, Creating OER and Combining Licenses - Full, by TheOGRepository, published on Sep 5, 2012

The OER Starter Kit Workbook

Retain
the right to make, own, and control copies of the content

Reuse
the right to use the content in a wide range of ways (e.g., in a class, in a study group, on a website, in a video)

Revise
the right to adapt, adjust, modify, or alter the content itself (e.g., translate the content into another language)

Remix
the right to combine the original or revised content with other open content to create something new (e.g., incorporate the content into a mashup)

Redistribute
the right to share copies of the original content, your revisions, or your remixes with others (e.g., give a copy of the content to a friend) 

This material was created by David Wiley and published freely under a Creative Commons Attribution 4.0 license at: http://opencontent.org/blog/archives/3221

• Noba - Psychology Modules A series of modules in the field of Psychology from Introductory courses to more advanced topics.
• Psychology (higher ed level) resources from OER Commons
• Quantitative Undergraduate Biology Education and Synthesis (QUBES): A repository contains learning materials, software, data, and models for teaching quantitative skills in undergraduate biology courses. QUBES is developed in part by faculty at the University of Pittsburgh.
• PhET Science Simulations: These interactive tools from the University of Colorado at Boulder are mostly CC licensed.
• National Science Digital Library - A collection of OERs in STEM subjects.
• Crash Course Series: Computer Science
• Computer programming at Khan Academy
• Open Chemistry, by the University of California, Irvine - Selected courses including required lecture courses for undergraduate UCI Chemistry majors and some electives and graduate courses. Video lectures are licensed CC BY SA 3.0.
• Chemistry LibreTexts: A collection of Chemistry open-access texts.
• Starting Point: Teaching and Learning Economics: This site introduces economists to innovative teaching strategies developed both within and beyond the discipline of economics.
• ​Courseware from Sloan School of Management (CC BY NC, SA)
• HippoCampus: a collection of free educational resources by subject
• OER Commons on Language Education (ESL) 

Open Courses

• Saylor.org: Offers full courses online. Though they charge students to enroll, they have composed their courses using mostly open materials that can be copied, adapted, etc.
• Open Course Library: This WA project offers 81 of Washington's most enrolled courses. There are a lot of great readings in these course files. Great community college content.
• Open Learning Initiative: Complete courses from Carnegie Mellon University
• MIT Open Courseware: Open courseware developed by MIT.
• OpenLearn: All of the learning materials presented on this site are CC licensed, but don't confuse "Learning Spaces" with the full Open University- their licensing/copyrights are different.
• EdX: A collection of college-level courses from a variety of high-profile universities. Some course materials are freely licensed for reuse.

Open Textbooks

• BCcampus Open Textbooks Collection
• Open Textbook Library: Hundreds of complete, open college-level textbooks. Many include peer-reviews.
• Open Stax: Rice Connexions is providing peer reviewed, quality open textbooks.
• Open Textbooks SUNY: this site has textbooks developed by the State University of New York.
• Open Textbooks list by subject: a list of open textbooks by subject compiled by Sacred Heart University.
• LibreTexts: a collection of open textbooks 
• Project Gutenberg free books
• EdTechBooks completely free ebooks by industry-leading professors and other experts
• Open Textbooks of Hong Kong including university level open textbooks.

Open Repositories

• OER Commons: Offers a variety of OER at a variety of levels and subjects. Use limiters on left side of results page.
• OASIS: OASIS (Openly Available Sources Integrated Search) offers the ability to search a range of OER materials from multiple sources, such as textbooks, courses, corresponding materials, interactive simulations, and public domain books and resources.
• MERLOT: One of the biggest OER repositories, but a bit unwieldy and difficult to search. Use limiting options on the left side of results page.
• Mason OER Metafinder: Searches 15 OER repositories simultaneously. 
• Applied Math and Science Education Repository (AMSE)
• OAPEN - Online Library and publication platform; open access publishing in European networks
• OER World Map - Enabling the exchange of data, experiences and ideas among open educational actors and communities.

Open Images and Multimedia

• Creative Commons Search
  Creative Commons has created this really useful search engine that lets you search for resources that are CC licensed. The image search is the most useful.
• flickr CC (flickr Creative Commons)
• Unsplash (No cost. No attribution required)
• 31 Free Public Domain Images Websites
• TED Inspiring thinkers on a range of subjects present big ideas and lectures on a regular basis- completely CC licensed.
• Wikimedia Commons: The thinkers behind Wikipedia bring you images, video and music all openly licensed or in the public domain.
• Khan Academy Hundreds of short educational videos covering many subjects; especially strong collections in science and math.

• Creative Commons Search
  Creative Commons has created this really useful search engine that lets you search for resources that are CC licensed. The image search is the most useful.
• flickr CC (flickr Creative Commons)
• Unsplash (No cost. No attribution required)
• 31 Free Public Domain Images Websites
• TED Inspiring thinkers on a range of subjects present big ideas and lectures on a regular basis- completely CC licensed.
• Wikimedia Commons: The thinkers behind Wikipedia bring you images, video and music all openly licensed or in the public domain.
• Khan Academy Hundreds of short educational videos covering many subjects; especially strong collections in science and math.

Citing OERs in APA

eBook

Lincoln, A., Koschmider, A., Salciccoli, A., Wregglesworth, K., Pontoni, M., Wozniak, M., . . . Kilgus, T. (2017) World history. Retrieved from http://www.oercommons.org/courses/world-history/view. CC BY-NC-SA 4.0 license.

Image

Roe, K. (2012, April 22). Leads castle [Photograph]. Retrieved from https://flic.kr/p/c35GPj. CC BY 2.0 license.

Video

Khan Academy. (2017, January 16). History and prehistory: The origin of humans and human societies [Video file]. Retrieved from https://www.youtube.com/watch?v=Pz3XiJac57w. CC BY license.

Citing OERs in MLA

eBook

Lincoln, A. et al. Human Rights. MIOpenBook, 2017. OER Commons, http://www.oercommons.org/courses/world-history/view. Accessed 29 January 2019. CC BY-NC-SA 4.0 license.

Image

Roe, Karen. Leads Castle. 2012 Online image. Flickr. Web. 29 January 2019. Retrieved from https://flic.kr/p/c35GPj. CC BY 2.0 license.

Video

“History and Prehistory: The Origin of Humans and Human Societies.” YouTube. Uploaded by Khan Academy. 16 January 2017, https://www.youtube.com/watch?v=Pz3XiJac57w. <https://flic.kr/p/c35GPj> CC BY license.