MDPI (Multidisciplinary Digital Publishing Institute) is a publisher of open access scientific journals. Founded by Shu-Kun Lin as a chemical sample archive, it now publishes over 390 peer-reviewed, open access journals. MDPI is the largest open access publisher in the world and the fifth largest publisher overall in terms of journal paper output. The number of published papers has been growing significantly in the last decade with year over year growth of over 50% in 2017, 2018 and 2019.