James Clark has been involved with SGML and XML for more than 10years, both in contributing to standards and in creating open sourcesoftware. James was technical lead of the XML WG during the creationof the XML 1.0 Recommendation. He was editor of the XPath and XSLTRecommendations. He was the main author of the DSSSL (ISO 10179)standard. Currently, he is chair of the OASIS RELAX NG TC and editorof the RELAX NG specification.The open source software that James has written includes SGMLparsers (sgmls and SP), a DSSSL implementation (Jade), XML parsers(expat and XP), an XPath/XSLT processor (XT) and a RELAX NG validator(Jing). Prior to his involvement with SGML and XML, James wrote theGNU groff typesetting system.James read Mathematics and Philosophy at Merton College, Oxford,where he obtained First Class Honours. James lives in Thailand, wherehe runs the Thai Open Source Software Center.