To be able to provide open access journals, MDPI finances publication though article processing charges (APC); these are usually covered by the authors' institutes or research funding bodies. Journals published include Molecules (launched in 1996; Impact Factor 2.428), The International Journal of Molecular Sciences (launched in 2000; Impact Factor 2.464), Sensors (launched in 2001; Impact Factor 1.953), Marine Drugs (launched in 2003; Impact Factor 3.978), Energies (launched in 2008; Impact Factor 1.844), The International Journal of Environmental Research and Public Health (launched in 2004; Impact Factor 1.998), Viruses (launched in 2009; Impact Factor 2.509), Remote Sensing (launched in 2009; Impact Factor 2.101), Toxins (launched in 2009; Impact Factor 2.129) and Nutrients (launched in 2009; Impact Factor 2.072). Their publishing activities are supported by more than 5000 active scientists on the journals' international editorial boards, including several Nobel Laureates. More than 120,000 individual authors have already published with MDPI, and 350,000 scholars are in the pool of reviewers. MDPI aims to have all of its journals covered by the Science Citation Index Expanded (SCIE) and Scopus indexing systems. Several journals have already been covered by SCIE for several years and have received official impact factors. Some life-science related journals are also covered by PubMed/MEDLINE and archived through PubMed Central (PMC). All the journals are archived with the Swiss National Library.