Open-access literature is digital literature, both peer-reviewed and popular, that is available on the web, free of charge, and free of most copyright and licensing restrictions. Committing to open access requires dispensing with the financial, technical and legal barriers that are designed to limit access to scientific research articles to paying customers.
The only constraint on reproduction and distribution, and the only role for
copyright in this domain, should be to give authors control over the
integrity of their work and the right to be properly acknowledged and
cited. - from the Pakistan National Digital Library
Here are some resources for educators and researchers made possible by open access principles.
Auraria Library Open Access info
Library Publishing Media
Directory of Open Access Journals
Elektronische Zeitschriftenbibliothek Universitaet Regensburg
FFT: Free Full Text
Public Library of Science