Altova XML Spy
   A comprehensive product-line of software tools that consists of the XSLT Stylesheet Designer, the XML Spy Document Editor, and the XML Spy Integrated Development Environment, which includes an XML editor, XSLT editor, and graphical XML Schema designer. [
   http://www.xmlspy.com/

EditML Pro
   NetBryx Technologies' integrated development environment (IDE) tool; XML, DTD and Schema editor; also validation, XSLT transformation, browser preview and automatic DTD and XSL generation.
   http://www.netbryx.com/EditMLPro.aspx

Stylus Studio
   Sonic Software's platform for an XML development environment that includes an XML Schema editor, XSLT editor, XML-XML mapper, debugging and document wizards. [Commercial]
   http://www.sonicsoftware.com/products/sonic_stylus_studio/

Tagfree2000
   Contains XML, DTD, and SMIL editors. [Commercial]
   http://www.tagfree.com

XMLWriter
   A validating XML text editor for Windows that supports XML, XSL, DTD, CSS, and HTML files. [Shareware]
   http://XMLwriter.net/

XMLmind XML Editor
   XXE, for short, is a full-fledged XML 1.0 editor featuring a word processor-like view (CSS2 styled). It has been created to make technical persons comfortable and productive at editing XML documents and XML data. [Open Source]
   http://www.xmlmind.com/xmleditor

XMetaL
   A document-centric authoring tool for XML and SGML. [Commercial]
   http://www.xmetal.com/

XmlTool
   Mouse-based editor for XML files, that generates HTML, XSL, DTD files, and gets Database structure and queries. [Shareware]
   http://www.xml.com/pub/p/17

epcEdit
   Validating XML/SGML document editor for Windows, Linux, and Solaris. [Commercial]
   http://www.epcedit.com/