"Open access (OA) literature is digital, online, free of charge, and free of most copyright and licensing restrictions
The Open Access movement dates back to the early '00s, although discipline-specific initiatives began earlier. One of the first formal declarations of the movement's principles was the Budapest Open Access Initiative
(2002), defining "world-wide electronic distribution of the peer-reviewed journal literature and completely free and unrestricted access to it by all scientists, scholars, teachers, students, and other curious minds" as a public good.
The two most commonly-used mechanisms for achieving open access are often called the ‘gold’ and ‘green’ routes:
- Gold – publishing your output on a platform which provides immediate e-access for everyone, free of charge, with a licence which permits re-use. Publishers can recoup their costs through a number of mechanisms, including through payments from authors (known as article processing charges, or APCs), or through advertising, donations or other subsidies. Some publishers operate a 'hybrid' model, with open and paywalled articles on the same platform.
- Green – providing open access to the author's final manuscript or published output in a searchable archive, commonly known as a repository, maintained by the author's institution or a scholarly society/professional body. The publisher may impose an embargo on open access to the file, normally in a range of 6 to 24 months.