Creative Commons licenses have become the gold standard of open licenses. There are now well over a billion items using Creative Commons licenses. This includes Open Access articles, with the majority of articles using CC-BY, and Open Educational Resources (OER). There are tens of millions of original videos on YouTube with a Creative Commons license, and hundreds of millions of images on Flikr. Creative Commons Licenses are most often used for items like, books, plays, movies, music, articles, photographs, blogs, and websites. Although one can use a Creative Commons License for software, because there is a well developed open licensing ecosystem for software, Creative Commons suggests using a license specifically designed for software.
Under the terms of the licenses, the copyright holders (licensors) still retain their copyrights and grant usage rights to the public (licensees). The licenses offer creators an array of choices with regards to the permissions they will grant to others.
Works made available under a Creative Commons Licenses are indicated with a symbol followed by one or more requirements to use the work. Creative Commons works can have up to four rights attached to the licenses. These rights add or subtract certain permissions and can be combined into six different CC licenses.
Creative Commons by Salah Mengerti CC BY 2.0
CC Licenses have three layers
© 2011, Creative Commons,
Nathan Yergler, Alex Roberts. CC-BY 3.0 Unported
The earlier iterations of the CC licenses came in two versions: Unported, which means not associated with any specific jurisdiction, and Ported, meaning that they been tailored to the legal conventions of particular jurisdiction. Although they are designed to have the same effect anywhere in the world, the use of a Ported License in a different jurisdiction could create issues with different interpretations of terms, such as what constitutes a derivative work.