Small & Fast & Free product for making XML-documents.
Microsoft XML Notepad ,
Microsoft® XML Notepad is a simple prototyping application for HTML authors and developers that enables the rapid building and editing of small sets of XML-based data. With XML Notepad, developers can quickly create XML prototypes in an iterative fashion, using familiar metaphors.
I really like this product and I been using it with small projects. It's comes handly, because it's easy and you know all the time what you are doing

Only weak thing is that it's still "Beta" and seems like Microsoft have something else on mind, because last update is from May 15, 1999.
Microsoft had deleted the file from the website (

? ) , But you can still get it from
Webattack's websiteGo for,