"Open-access (OA) literature is digital, online, free of charge, and free of most copyright and licensing restrictions. What makes it possible is the internet and the consent of the author or copyright-holder." (Peter Suber)
In addition to scholarly publications, the Open Access Movement also includes Open Science, Open Data, and Open Education - freeing the research process for even quicker dissemination of knowledge and more rapid discovery.
This method allows the author to place a version of the published research in various platforms, including disciplinary repositories (e.g. ArXiv or PubMed Central), institutional repositories (e.g. ODU Digital Commons), or personal webpages.
Some publishers allow their final version (usually a pdf) to be self-archived, while others only allow the author’s pre-print or post-print (final version after peer-review) to be self-archived either immediately or after an embargo period. Publisher policies on self-archiving and versions are available in either the SHERPA/RoMEO database or on the publisher or journal website (usually more up to date than SHERPA).
The Gold OA method makes published works available immediately on publication.
Many publishers require the author to pay an Article Processing Charge (APC) for immediate open access. Public Library of Science (PLoS) and BioMed Central are examples of Gold OA publishers.
With Hybrid OA, publishers of subscription-based journals offer an OA option to authors (with an APC, sometimes up to $5,000). With this option, an individual article is openly available immediately, while the other articles are still available only through subscription.
A true Open Access journal: there is no cost to the author or reader, because these journals are often sponsored by universities, government information centers, or even groups of researchers.
Publishers can choose to make an article freely available to read (with no APC), but they can also end the free availability at any time.
Self-publishing of books has become a viable option for some scholars interested in taking a more independent approach to distributing their works in an open access framework. Publishers and university publishers are also developing open access book programs and open textbook programs. The Directory of Open Access Books indexes academic, peer reviewed, open access books that are made publicly available under various types of licenses. The license terms associated with each book display as a link.