The Aristotle Metadata Registry (or Aristotle-MDR) is an open-source Metadata Registry framework based on the ISO/IEC 11179 standard for Metadata Registries. It is influenced by the AIHW Meteor Metadata Registry and the Canadian Institute of Health Information Indicator Bank. Aristotle-MDR is designed to describe data holdings databases and associated structural metadata. The Aristotle Metadata Registry was publicly launched at the 2015 IASSIST Conference in Toronto.