I believe that it was used previously in the ATOC advanced to export the flightplan to FSBuild format, then you could import it into the FS9 GPS or your FMS/FMC.
However I don't think FS Build is used very widely in England, it seems to be more of a European thing as an alternative to FSNav/FSc/FOC
Peter Dodds wrote:
What does the FSBuild Button do in the flight plan window? Peter