Open access (OA) is the free, online availability of scholarly journal articles, including peer-reviewed materials, and primarily in reference to those which authors publish without expectation of payment.
Open Access can refer to publishing initiatives where journals make their articles freely accessible immediately on publication, or to self-archiving initiatives where authors make copies of their own published articles freely accessible via a subject-based or institutional repository.
According to the Directory of Open Access Journals about 10% of peer-reviewed journals are now OA journals. According to SHERPA / RoMEO over 90% of peer-reviewed journals have endorsed some form of self-archiving.
OA self-archiving Authors publish in a subscription journal, but in addition make their articles freely accessible online, usually by depositing them in an institutional repository such as the E-Commons at Mount Saint Vincent University. This is one of two methods for providing open access and may be referred to as The Green Road to Open Access.
OA publishing Authors publish in open access journals that make their articles freely accessible online immediately upon publication. Publishing in an open access journal is the second method for providing open access and may be referred to as The Gold Road to Open Access.
Pre-print In most instances this is the version of an article before peer-review. However, some publishers use pre-print to mean a peer-reviewed and amended article that has not yet been type-set or formatted for publication.
Post-print The version of the article after peer-review and final revision i.e. the version intended by the author for publication, but before the publisher's type-setting and formatting. In most cases it is the author's post-print, not the publisher's formatted version, that is deposited in the E-Commons.
DOAJ The Directory of Open Access Journals which lists and indexes peer-reviewed, open access scientific journals.
OJS An acronym for Open Journal Systems, open source publishing software developed by the Public Knowledge Project in Canada and now used around the world.
PLoS The Public Library of Science, an advocacy organization and open access publisher of high quality scientific open access journals.
SPARC An acronym for Scholarly Publishing and Academic Resources Coalition. SPARC was developed in 1997 by the Association of Research Libraries to address the crisis created by rising journal subscription costs and declining academic library budgets. Open access was proposed as a possible strategy to address the crisis.
Among some of the names associated with the promotion of Open Access are:
Stevan Harnad who first formally proposed OA self-archiving in 1994. Authors publish in a subscription journal, but also make their articles freely accessible online, usually depositing them in an institutional repository like the Mount Saint Vincent University E-Commons. This approach is referred at as the "green" road. Harnad maintains a blog called Open Access Archivangelism.
Paul Ginsparg who initiated the first free scientific archive in 1991. arXiv.org was initially a pre-print service for physicists, but now includes papers from related disciplines such as computer science and mathematics. Self-archiving has become the norm for physics.
Harold Varmus who in 1999 proposed an open access electronic publishing platform combining a pre-print server with peer-reviewed articles. E-biomed became PubMed Central, a post-print archive. The original E-biomed proposal has been realized more closely in BioMed Central. Varmus is the co-founder of the Public Library of Science, an open access publisher.