XMLMate (formerly TeXMLMate) is a TextMate PlugIn - 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, XML Catalogs, XInclude, and XPath Visualization.
Version 1.4.3: works with TextMate 1.5.7. If you are using TextMate version 1.5.7 or later, you will need XMLMate 1.4.2 or later. Earlier versions of XMLMate will not work with TextMate 1.5.7 or later. I've also added a user default for making the XMLMate panel a non-floating window:
defaults write com.macromates.TextMate XMLMateFloatingPanel -bool NO
INSOMNIS The addition of XPath was just what I was waiting for to come out of this tool. Great add-on for validating and tinkering with XML in TextMate. I like the validation much better than the built in support. Thank You. (Version 1.4)