I don't think I have unreasonable requirements. I want an XML editor that does validation as I edit, that validates against XML Schema, and validates documents with elements and attributes from multiple namespaces. It should run on Windows.
I'm doing this for producing a document with SOAP 1.2 messages and various extension headers. I've had all sorts of problems with what used to be my favorite tool - XMLSpy. I just can't get it to reliably validate documents across mutiple schema.
Today, I found XRay2 from Architag. A free download (with registration). I'm still trying it out, but it does just what I need in an intuitive way. Load all the schema in the validator, and it builds a catalog from the declarations in the schema, and you can then build an XML document using all the namespaces defined in that catalog. Simple, intuitive, and just what I need.
And its free!
