Many InChIs and quite some feat

Fifteen years have passed since the International Union of Pure and Applied Chemistry (IUPAC) international chemical identifier (InChI) project [1–8] was initiated in 2000. The increasing complexity of molecular structures was making conventional naming procedures inconvenient, and there was no suitable, openly available electronic format for linking chemical structures over the Internet. So, InChI was developed as a freely available, non-proprietary identifier for chemical substances that can be used in printed and electronic data sources, thus enabling easier linking of data compilations and unambiguous identification of chemical substances. It was developed under the auspices of IUPAC, with principal contributions from the US National Institute of Standards and Technology (NIST), and more recently, the InChI Trust [9]. The Trust is a notfor-profit organization that develops and improves on the current standard. InChI is freely available under terms even less restrictive than those of the GNU Lesser General Public License. Any organization can use it, in either public or private databases. The source code and associated software, documentation, and licensing conditions can be downloaded free from the InChI Trust website. InChI is written in C and can be compiled on most systems. Version 1 was launched in 2005. The current version (1.04) was released in September 2011. InChI is not a registry system: it does not depend on the existence of a database of unique substance records to establish the next available sequence number for any new substance. InChI is not a replacement for any existing internal structure representations; indeed, it is often used in addition to an internal representation [10]. Its value is in finding and linking information. An InChI string is not directly intelligible to the human reader; like bar codes, InChIs are not designed to be read by humans. The InChI certification suite is a software package developed and designed to check that an installation of the InChI program has been performed correctly. The programs test an installation against a broad set of structures which are provided with the suite. Once the programs are run and the results sent back to the Trust, an ‘‘InChI certified’’ logo is sent to the applicant. The InChI Trust certification logo can then be put on the pages of the applicant’s website.