Many events came together to focus attention on the need to increase access to information and importantly to make OA a practical possibility. You can view the details on the timeline of the open access movement but a few of the early highlights include:
Under Open Access, literature “… is digital, online, free of charge, and free of most copyright and licensing restrictions.” Peter Suber, Senior Researcher for the Scholarly Publishing and Academic Resources Coalition (SPARC). It contrasts with the most prevalent and traditional method of scholarly communication in which publishers obtain copyright from authors and disseminate research literature for a fee to subscribers.
Generally speaking there are three:
1. Self-archiving involves the direct deposit of scholarly works into an open repository often defined by subject (sometimes called a central repository – PubMed Central is one example) or by institution (an institutional repository or IR). It is not a publishing method and its express purpose is to make information as accessible as possible. Self-archived works may be published, to-be-published (pre- and post-prints), or unpublished (many theses and conference papers). Besides text, content may contain data or be multimedia in format. This route to OA is known as the GREEN Road.
2. OA journals publish scholarly information and give full text access for free. There are a growing number of these journals including those associated with the Public Library of Science (PLoS) and BioMed Central. In the traditional system of scholarly communication, the publisher subsidizes the costs of journal production and distribution through individual and institutional (primarily library) subscribers, i.e., the “readers.” OA journal publishers on the other hand, have different business models, only one of which is the “author-pay” approach in which the authors not the readers fund the costs of publishing articles online. Unlike works in an IR, research articles in these OA publications are largely peer-reviewed, some very selective of their content. This route is called the GOLD Road.
3. Increasingly OA proponents identify a third model, the Hybrid OA model. Here publishers offer authors the option of open access of their works for a fee. For example, under Springer’s Open Choice program for a $3000 fee, authors can retain copyright and freely distribute their published works.