The links in this Guide have all been selected on the basis of their providing content that you can use freely (or in the case of iTunes, embed and your students pay a low price for) in your online courses. You do not need to get permission from the intellectual property owner, and you do not need to pay for them.
Acknowledging your source is a key part of academic integrity that is separate from copyright issues. In all cases, you should cite the creator of the product, whether it's a text file, image, music file, or video clip.
If you discover a source of public domain, creative commons, or free-for-education resources, please let me know at firstname.lastname@example.org. We are always looking to expand and improve our Guides!
The public domain is created by United States copyright law. US copyright law specifies that copyright protection only lasts for a certain amount of time before the work falls into the public domain and can be used without permission and without any fee. The reasoning behind this is that copyright law must balance the needs of the work's creator to make a profit with the needs of society to advance human knowledge by borrowing from and adapting the works of others.
The laws governing public domain have changed over time. Copyright protection lasts longer and longer, and is now guaranteed without the creator going to any effort to register their work with the copyright office.
Because of all these changes in the law, it is very difficult to guess whether a work is in the public domain. To help you, the ALA Office for Information Technology Policy created this Digital Copyright Slider. You just move the red arrow on the right side of the page to the appropriate publication date, and the left side of the page will help you make your determination.
You may have to look up the year of the author's death; to do that, use the New General Catalog of Old Books and Authors.
Creative Commons is a set of ready-made licenses that a content creator can use on their own work. Although they continue to hold the copyright, they have licensed some of their rights to everybody, within the set conditions. Creative Commons licenses are rock-solid legal and legit - they have held up in the Supreme Court. The four basic license conditions, which can be used in any combination, are:
There's also public domain or "CC0", in which the content creator donates the work to the public domain and you can use it freely, and "Founders' Copyright," in which the content creator retains rights for 14 years after its creation and then the work goes into the public domain.
Learn more here: Creative Commons - About CC Licenses.