What is the format of the GPS data?
The data comprises all of the numbered waypoints that correspond to the instructions in the book. The files are in Garmin gpx format. If you need the data in another format then GPSBabel is a widely used tool.
Do I need a GPS to use the Lightfoot Guides?
The guides a designed to be self contained and it is not necessary to use a GPS. However, some people prefer the security of also having data on a GPS unit or Smartphone.
What is the latest edition of the Lightfoot Guide to the via Francigena?
Edition 6 was released in April 2014 in both paperback and E-book. A very minor revision will be released in E-book form only in December, 2014