Cladonia Exchanger XML Editor 3.2
http://www.hyperwrite.com/Articles/showarticle.aspx?id=62

Self, Tony
HyperWrite
2006

Abstract:

Having spent some time working with Cladonia's Exchanger XML Editor, I can attest to the claim that this is a good, solid, well-featured and extensible XML editor. However, the software is not suitable for authoring documents. It is designed for working with XML data in many forms, but it is not designed for textual content. Let me explain.