Oxygen is a multi-platform XML Editor, XML Author, XSLT/XQuery Debugger and Profiler. Supports visual XML editing driven by CSS stylesheets. It supports XML, XSL, XQUERY, FO, XSD, RNG, RNC,NRL, DTD, Schematron, WSDL and CSS documents. It offers a powerful and intelligent code insight that guides the user to write valid XML content.