XMLMate

XMLMate ist ein XML/DTD/XSD/RNG/Schematron/XInclude/XPath Plug-In für TextMate

Check XML and XHTML documents for Well-Formedness and Validity while editing them in TextMate with support for DTD, W3C XML Schema, RELAX NG, Schematron, XInclude, XML Catalog, and XPath 2.0 Visualizer.

via Code Candies