From Istaria Lexica
There doesn't seem to be an official resource for that tool anymore.
- download and unpack the zip file
- move the created folder somewhere (preferably into your 'program files' location)
- optional: create a link to the 'AGHViewer.exe' file on your desktop
- double click 'AGHViewer.exe' to start the tool
Incase you have troubles to get it running you may find help by asking other players on the istaria community boards.