Free XML editor
 

That looks like a pretty nice editor.

Just because options are always good, this is a nice free xml editor as well:
Peter's XML Editor

Heres mine
Crimsion Editor

Hi there,

Hey bro! Nice link I liked it.Thanks for such a nice link that you share with us.It helps me a lot.

Thanks again:-

Here is the one I use:

Notepad++

I use Visual Web Developer Express 2008 from Microsoft. Very nice editor, you can apply css, transforms, and schemas to the xml file. The extensive options for customizing the editor behavior is also real nice, all of the Visual Studio Express allow you to create template files, like the template I use is just the barebones EQUI Xml file, so when I hit New my EQUI Xml Template shows up in the list. I think you would have a hard time finding a better editor once you get used to the VS08 stuff.

how about writing a little "getting started" tutorial for that Shilling ? anything to help get a visual idea of what i can/want to change in my current UI pieces i want to modify

Microsoft's Visual Studio Express is superb, and Notepad++ is good too, but I've recently discovered another free one that works on Linux and Windows:
http://xml-copy-editor.sourceforge.net/

It's not perfect, but it's got some really nice touches like the ability to collapse and expand the XML on screen. The best feature by far though is the autocompletion of xml elements, which picks up suggestions intelligently from the rest of the page.

It means that within a gauge, you can start typing "Gau" and it will suggest "<GaugeOffsetX>" and "<GaugeOffsetY>" as options, and will automatically fill in the </GaugeOffsetX> entry for you as well.