The mouseover window indicator in the default debugging window can be usefull, but often you need more information. Rather than type commands over and over to find the dimensions, the anchors, and so forth, you can use Drill. Not only does drill show this information for the selected window, but it also drills down through all the ancestors that it can fit on the window.

Drill shows the following information:
Current mouse coords, both UI pixels and in screen pixels
For each processed window:

1. Window name
2. Whether window is hidden
3. Window alpha
4. Window dimensions
5. Window position in UI pixels and screen pixels
6. Window anchors

Drill can display this information for either the mouseover window, or for one you specify.

Commands: (LibSlash is required)
/drill -- Open the window, reset to monitor window under mouse
/drill WindowName -- Monitor WindowName

When monitoring a specific window, the window name will be in red to indicate this.