[http://ditchnet.org/xmlmate XMLMate Homepage] 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.

4Suite is a platform for XML processing and knowledge management, implemented in Python and C. It's split into three separate packages: 4Suite XML - XML, XPath, XSLT, related technologies and support libraries 4Suite RDF - RDF processing libraries and stand-alone DBMS 4Suite Repository - XML a...