The Crystallography Open Database (COD) is an open-access collection of crystal structures, aiming to gather all available inorganic, metal–organic, and small organic molecule structural data. Founded in February 2003 in response to Michael Berndt's letter, the COD has grown to contain approximately 80,000 entries in crystallographic information file (CIF) format, with nearly full coverage of International Union of Crystallography publications. The database is maintained by a team of scientists and supported by various institutions and volunteers. It includes both experimentally determined and computationally predicted structures, with the Predicted Crystallography Open Database (PCOD) focusing on predicted structures. The COD and PCOD are available for online search and download, and the COD has implemented automated procedures for data deposition, validation, and correction. Future developments aim to enhance efficiency, introduce a substructure search engine, and improve user interface and functionality.The Crystallography Open Database (COD) is an open-access collection of crystal structures, aiming to gather all available inorganic, metal–organic, and small organic molecule structural data. Founded in February 2003 in response to Michael Berndt's letter, the COD has grown to contain approximately 80,000 entries in crystallographic information file (CIF) format, with nearly full coverage of International Union of Crystallography publications. The database is maintained by a team of scientists and supported by various institutions and volunteers. It includes both experimentally determined and computationally predicted structures, with the Predicted Crystallography Open Database (PCOD) focusing on predicted structures. The COD and PCOD are available for online search and download, and the COD has implemented automated procedures for data deposition, validation, and correction. Future developments aim to enhance efficiency, introduce a substructure search engine, and improve user interface and functionality.