molecular dynamics, and plane-wave density-functional-theory software programs. It also supports a flexible framework for generating input files for various software packages. For a complete list of supported formats, please go to https://iodata.readthedocs.io/en/latest/formats.html. A number of tools intended for viewing and editing molecular structures are able to read in files in a number of formats and write them out in other formats. The tools JChemPaint (based on the Chemistry Development Kit), XDrawChem (based on OpenBabel), Chime, Jmol, Mol2mol and Discovery Studio fit into this category. The Chemical MIME Project "Chemical MIME" is a de facto approach for adding MIME types to chemical streams. This project started in January 1994, and was first announced during the Chemistry workshop at the First WWW International Conference, held at CERN in May 1994. ... The first version of an Internet draft was published during May–October 1994, and the second revised version during April–September 1995. A paper presented to the CPEP (Committee on Printed and Electronic Publications) at the IUPAC meeting in August 1996 is available for discussion. In 1998 the work was formally published in the JCIM. Support For Linux/Unix, configuration files are available as a "chemical-mime-data" package in .deb, RPM and tar.gz formats to register chemical MIME types on a web server. Programs can then register as viewer, editor or processor for these formats so that full support for chemical MIME types is available. Sources of chemical data Here is a short list of sources of freely available molecular data. There are many more resources than listed here out there on the Internet. Links to these sources are given in the references below. The US National Institute of Health PubChem database is a huge source of chemical data. All of the data is in two-dimensions. Data includes SDF, SMILES, PubChem XML, and PubChem ASN1 formats. The worldwide Protein Data Bank (wwPDB) is an excellent source of protein and nucleic acid molecular coordinate data. The data is three-dimensional and provided in Protein Data Bank (PDB) format. eMolecules is a commercial database for molecular data. The data includes a two-dimensional structure diagram and a smiles string for each compound. eMolecules supports fast substructure searching based on parts of the molecular structure. ChemExper is a commercial data base for molecular data. The search results include a two-dimensional structure diagram and a mole file for many compounds. New York University Library of 3-D Molecular Structures. The US Environmental