a free source code editor which supports several programming languages running under the MS Windows environment. based on Scintilla edit component (a very powerful editor component)
XRay is a free XML editing enviroment. Now in its second major release, XRay provides support for XML Schema (XSD) and an integrated online XML tutorial system.
Altova SemanticWorks™ 2007 is the ground-breaking visual RDF/OWL editor from the creators of XMLSpy. Visually design Semantic Web instance documents, vocabularies, and ontologies then output them in either RDF/XML or N-triples formats. SemanticWorks™