PUBLIC MARKS with tags editor & xml

Very good opensource editor

EditiX is a powerful and easy to use XML editor, Visual Schema Editor, XQuery Editor and XSLT debugger for Windows, Linux and Mac OS X designed to help web authors and application programmers take advantage of the latest XML and XML-related technologies such as XSLT / FO, DocBook and XSD Schema. EditiX provides users with an extensive range of XML functionality within a refined IDE that guides you with intelligent entry helpers. EditiX has realtime XPath location and syntax error detection. Helpers are also provided with context syntax popup supporting DTD, Schema and RelaxNG. EditiX supports multiple templates and project management. User can apply XSLT, XQuery or FO Transformation and show the result with a dedicated view. All the process can be managed by shortcuts. Working locally is managed with OASIS XML Catalogs. EditiX includes default templates with XML, DTD, XHTML, XSLT, XSD, XML RelaxNG, SVG, MathML and XML FO.

ML Copy Editor is a fast, free, validating XML editor

Turn TextMate into an XSTL/XQuery editor/debugger.

need (to give it a try)!

A pretty good and seem lightweight XML editor

Oxygen is a multi-platform XML Editor, XSLT/XQuery Debugger and Profiler written in Java. 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. The code insight can be driven by a DTD, an XML Schema, an RNG or by the structure of a partial edited document. Features SVN Client and native XML Databases support.

This is a self-paced tutorial on Laszlo XML markup language. Please follow the embedded instructions.