Oxygen is an XML Editor, XSLT/XQuery Debugger and Profiler with full Unicode support. It offers a code insight that can follow a DTD, Relax NG or an XML Schema, or even can learn the structure from a partial edited document. XML and XSL documents can be associated one with the other and the transformation results can be viewed as text or HTML. Oxygen provides a visual schema editor for W3C XML Schema and Relax NG schema designed to simplify the development and understanding of the schema files. Oxygen validates XML, XSL, XQUERY, FO, XSD, RNG, RNC, NRL, DTD, Schematron, WSDL, and CSS content, reporting errors with description and line number information and marking them in the document when validate as you type is enabled.