The Directory of Open Access Journals (DOAJ) is a service that provides access to quality controlled Open Access Journals. The Directory aims to be comprehensive and cover all open access scientific and scholarly journals that use an appropriate quality control system, and it will not be limited to particular languages or subject areas. The aim of the Directory is to increase the visibility and ease of use of open access scientific and scholarly journals thereby promoting their increased usage and impact. How are Open Access Journals defined? In their words: “as journals that use a funding model that does not charge readers or their institutions for access. From the BOAI (Budapest Open Access Initiative) definition  of “open access” we take the right of users to “read, download, copy, distribute, print, search, or link to the full texts of these articles” as mandatory for a journal to be included in the directory.”
The National Institutes of Health Public Access Policy was enacted in 2008 to ensure that the public has access to the published results of NIH-funded research. It requires scientists to submit final peer-reviewed journal manuscripts that arise from NIH funds to the digital archive PubMed Central which is an archive of full-text biomedical journal papers available online without a fee.