Albert's (Simple) XML-editor
...formerly named "AXE", it's basically just a tree display with a menu.
The tree shows the structure of the document, but not as a pretty-printed text version. For instance, this display has no need or showing the end tags (they are implied). A possible drawback of this is that not well-formed documents cannot be viewed: instead you'll get an error message on loading.
Maybe I'll try to find a way to do something about that in the future.
The application currently has four menus, the first two are shown here:
I think they speak for themselves, except for the "Unlimited Undo" option. It is explained here: undo mechanism
The other two are:
On selecting an item in the tree, you can also have the menu pop up on the chosen location: to do so, right-click the item or select and use the menu key. This brings up a single menu so it looks a little bit different:
The file menu is not included because it contains functions for the entire file and the popup menu is about location-specific functions.
But the main strength (to me) is that all these functions can be executed using the keyboard. In fact, that is one of my requirements for apps like this.