When getting an image file from digital camera, users may think it just a picture. Actually, it contains a lot of information concerning the settings of the camera (eg. Exposure, F number) and so on. These information is contained in Exif tags, and it can give a lot of convenience to a photographer.
ExifViewer is an explorer externsion, it reads Exif tags and show these information to users. Users can export these information to files.