Todd Diychendorf has released Cocoatron 1.0, "a collection of Automator actions for graphically creating XML Processing Pipelines on Mac OS X." Cocoatron consists of six Automator Actions (composeable, configurable pipeline stages):
Cocoatron includes is based on libxml2 and supports XInclude, XSLT 1.0, EXSLT, XQuery, DTDs, W3C XML Schemas, and RELAX NG.