When I4OA was launched one year ago, the initiative was supported by 40 publishers, including Hindawi, Royal Society, and SAGE, who are founding members of the initiative. Among the initial supporters of I4OA there were commercial publishers (e.g., F1000, Frontiers, Hindawi, MDPI, PeerJ, and SAGE), non-profit publishers (e.g., eLife and PLOS), society publishers (e.g., AAAS and Royal Society), and university presses (e.g., Cambridge University Press and MIT Press). Some of the initial supporters of I4OA are open access publishers, while others publish subscription-based journals.
Over the past year, the number of publishers supporting I4OA has more than doubled. The initiative is currently supported by 86 publishers. Publishers that have joined I4OA over the past year include ACM, American Society for Microbiology, Emerald, Oxford University Press, and Thieme. I4OA has also been joined by a substantial number of national and regional publishers, for instance from countries in Latin America, Eastern Europe, and Asia.