This program mostly be a good xml editor really, despite it is meant to be a 'viewer' rather.
So I'd like to suggest some more feature like this:-
- Use [Insert] and [Ctrl] + [Insert] to add a new node under or beside the current node. (Currently there is only right click to do this.
- Remind and confirm if we are going to leave all edited item to 'New' XML. (I just lost my work when I press [Ctrl] + [N])

I like user interface design of WMHelp XMLPad and would like XML Viewer to get some of them.
However, I know that this is 'Viewer' not 'Editor' and the editing function is just surplus, not main feature.
I appreciate the simple editing function in XML Viewer.

Try XML EditPro for "tree editing function"
Try XMLPad for UI and other features (if you plan this program to be XML editor in the future )
Merging all good features together will come the best XML Editor.

Will add more once I get new idea
Thanks

Good job!!!
Actually I prefer Ctrl + Insert than Ctrl + I, it's ok because it's much easier to have keyboard shortcuts too.
Also I think double-click for editing value (by pop up a new dialog box to edit like Alt + Enter) is really good functioning this program should have.

However I found that I can not rename any single folder and attribute.
I tried 2 clicks (not double clicks) like renaming in Windows Explorer and other programs.
I tried to find 'Rename' in context menu (right click menu) but not found.
To work around this I have to create a new folder and move all child node into the new folder.

Although this may be just a hobby of yours and it says itself is just 'Viewer', I think it can beat many other XML 'Editor'(s) really.

You are right about the saving confirmation. I've also found that editing only the value of a tag does not trigger the 'dirty' flag so won't ask you to save later...

Anyways i'will fix that and upload a new version with the fix. Then there is a plenty of work to do on your other suggestions, probably will take 2-3 weeks and will release it as version 3 then

Regards
Meppy