James Webb Space Telescope use of XML

James Webb Space Telescope (JWST) has been defining, developing, and exercising the use of a common extensible markup language (XML) since 2002 for the central Project Reference Database (PRD) that would not only include the basic command and telemetry database structures, but also table definitions, pages, scripts, and other items needed for the real-time operations, archive, and planning systems. As part of the National Aeronautics and Space Administration (NASA) and the wider international space community, JWST has been working with the Jet Propulsion Laboratory (JPL), Object Management Group (OMG) and the Consultative Committee for Space Data Systems (CCSDS) XML Telemetry and Command Exchange (XTCE) personnel to provide the information needed by space systems for exchanging databases using a XML standard structure. This paper will discuss how JWST uses XML, the experience in the XML structure, exchanging databases with other users, and issues that have been experienced by JWST