Copernicus Publications has been publishing highly reputable peer-reviewed open access journals since 2001. Through interactive, multi-stage open access publishing, Copernicus aims to bring real transparency into scientific quality assurance. The Max Planck Society covers article-processing charges for Max Planck authors centrally. Further details are available on the MPDL website.

The collection licensed by the DFG comprises 1000 e-Books. In addition, access to 3,400 free electronic books from all subject areas is provided.

Frontiers is a community-oriented open-access academic publisher and research network. It was launched in 2007 by scientists from the Swiss Federal Institute of Technology in Lausanne and aims to provide better tools and services to researchers in the Internet age. Since then, Frontiers has become one of the fastest-growing open-access scholarly publishers: over 400,000 high-quality, peer-reviewed articles have been published in about 200 community-driven journals across more than 300 specialty niches in science, medicine and technology. The Max Planck Society covers article-processing charges for Max Planck authors centrally. Further details are available on the MPDL website.

GeoScienceWorld (GSW) is a nonprofit collaborative and comprehensive resource for research and communications in the earth sciences, which is built on a core database of peer-reviewed journals and is integrated with the GeoRef index. The platforms offers a single point of access to more than 40 full text scholarly journals from leading geoscientific organizations, plus specialized searching capabilities and links to millions of relevant resources hosted elsewhere on the Web. Though access to current volumes is no longer licensed, perpetual access rights have been granted to the content published until August 2018.

The database OLC Ibero-America, Spain and Portugal is a regional related section from the Online Contents database that is constantly being completed with the addition of selected journals from the competent Libraries, the Library of the Ibero-American Institute Prussian Cultural Heritage (Ibero-America and the Caribbean) and the state and university library SUB Hamburg (Spain and Portugal). Currently more than 1.400 journals are being indexed. Gradually earlier editions of these journals will also be made accessible.

PLOS (Public Library of Science) is a nonprofit publisher and advocacy organization founded to accelerate progress in science and medicine by leading a transformation in research communication. PLOS entered the publishing arena in October 2003 with the launch of PLOS Biology, followed in October 2004 by PLOS Medicine. Today, it publishes a suite of influential Open Access journals across all areas of science and medicine. The Max Planck Society covers article-processing charges for Max Planck authors centrally. Further details are available on the MPDL website.

SciELO (Scientific Electronic Library Online) is a program of the Sao Paulo Research Foundation for the cooperative publishing of open access journals on the internet. Content includes regional journals from Latin American and the Caribbean as well as titles from Spain, Portugal and South Africa. The index covers approximately 650 titles (over 350 adding content to journals already covered in the Web of Science) and contains several million cited references.

The MPI-Mainz-UV-VIS Spectral Atlas is a comprehensive collection of absorption cross sections for gaseous molecules and radicals, primarily relevant to atmospheric research, from measurements performed during the last nine decades. The individual data sets were collected from the original publications, either copied from tabulations, or read from figures in those cases where numerical data could no longer be obtained. Other sources rely on the internal databases of several research centers dealing with atmospheric chemistry and/or molecular spectroscopy. Numerous excellent high-resolution spectra were obtained from personal communications with the scientists.