Open Journal Systems, also known as OJS, is an open source and free software for the management of peer-reviewed academic journals, created by the Public Knowledge Project, and released under the GNU General Public License. OJS was conceived to facilitate the development of open access, peer-reviewed publishing, providing the technical infrastructure for the presentation of journal articles along with an editorial-management workflow, including article submission, peer-review, and indexing. OJS relies upon individuals fulfilling different roles, such as journal manager, editor, reviewer, author, and reader. It has a module that supports subscription journals. A single installation of OJS can support the operation of one or many journals. Each journal has its own unique URL as well as its own look and feel. OJS can enable a single editor to manage all aspects of a journal and the journal’s website, or OJS will support an international team of editors with diverse responsibilities for a journal’s multiple sections. This system is intended not only to assist with journal publishing, but to demonstrate how the costs of journal publishing can be reduced to the point where providing readers with “open access” to the contents of the journal becomes a viable option. The case for open access is spelled out over a wide series of articles stemming from this project which are freely available under Research > Publications on the Public Knowledge Project website. The system was first released in 2001 as a research and development initiative at the University of British Columbia, with the support of the Social Sciences and Humanities Research Council of Canada, the Max Bell Foundation, the Pacific Press Endowment, and the MacArthur Foundation. Its continuing development is currently overseen by the Simon Fraser University Library. For more information, see the Public Knowledge Project website https://pkp.sfu.ca/