Alternatives to Standard Copyright
In general, copyright law allows an author to prohibit others from reproducing, adapting, or distributing copies of the author's work. However an author or creator may choose to give every person who receives a copy of a work permission to reproduce, adapt or distribute the work, as long as any resulting copies or adaptations are also bound by the same licensing scheme. Using copyright law in this way is sometimes known as "copyleft."
Creative Commons Licenses
Creative Commons (www.creativecommons.org) has developed licenses which allow creators to maintain basic rights over their work, while automatically granting certain rights to anyone who wants to re-use their work.
The CC licenses are centered on the idea of "Some Rights Reserved" -- creators can choose what rights they would like to grant and what rights they want to restrict. For example a creator could restrict use of their work only to non-commercial uses, or a creator could let anyone do whatever they want as long as they are given credit for the original work.
Creative Commons licenses are very popular among creators of online content, since they make it much easier to re-use content on a website or blog.
The Free Software Foundation (www.fsf.org) created a set of licenses for developing freely distributed software. Their licenses have been used for other content -- for example, all the text in Wikipedia (en.wikipedia.org), and most of the images and other content, is covered by the GNU Free Documentation License
For more information, visit the Free Software Foundation and read about their copyleft licenses.
Scholarly Publishing and Academic Resources Coalition (SPARC)
SPARC ®, the Scholarly Publishing and Academic Resources Coalition, is an international alliance of academic and research libraries working to correct imbalances in the scholarly publishing system. Developed by the Association of Research Libraries, SPARC has become a catalyst for change. Its pragmatic focus is to stimulate the emergence of new scholarly communication models that expand the dissemination of scholarly research and reduce financial pressures on libraries. Action by SPARC in collaboration with stakeholders – including authors, publishers, and libraries – builds on the unprecedented opportunities created by the networked digital environment to advance the conduct of scholarship. (See Author Addendum to Publication Agreement)
Public domain comprises the body of knowledge and innovation (especially creative works such as writing, art, music, and inventions) in relation to which no person or other legal entity can establish or maintain proprietary interests within a particular legal jurisdiction.
Many people contribute work directly to the public domain, or are making works already in the public domain more accessible to more people. For example, Project Gutenberg (www.gutenberg.org) and LibriVox (www.librivox.org) both coordinate the efforts of people who transcribe works in the public domain into electronic form.
Creative Commons also has written a Public Domain Dedication which allows a rights holder to deed their work into the public domain whenever they choose.
It is important to remember that almost everything is automatically copyrighted at the point of creation, so do not assume that something is in the public domain just because it is freely available.
For more information, see What Is Covered By Copyright