1)   AltovaXML 2006
AltovaXML is a FREE XML standards processor that includes the Altova XSLT 1.0 engine, XSLT 2.0 engine, XQuery engine, and XML validator. Now developers can use the same processors found in Altova XMLSpy 2006 in their own applications, free of charge.
XSLT engine, XSLT 1.0, XSLT 2.0, XSLT, XQuery, XQuery engine, validating parser, standards processor, XML validator,