ChemSpider (http://www.chemspider.com/)6,7 is a free chemical structure database, containing information on 35 million structures collected from ~500 data sources. It also provides information on chemical reactions through ChemSpider SyntheticPages (CSSP)8. ChemSpider uses a crowdsourcing approach that allows registered users for manual comment and correction of ChemSpider records. Owned by the Royal Society of Chemistry (RSC), which publishes ~40 peer-reviewed chemistry journals, ChemSpider is integrated with the RSC publishing process, whereby chemicals species described in published RSC articles become available in ChemSpider.