http://www.gfbyars.com/winscore/

Winscore is a robust and easy to use Windows based scoring program
for soaring contests in the US. The scoring program is used at soaring contests
to calculate contestant speeds, distances, scores, and to generate score sheets.
The scoring program also can generate .zip files which contains the GPS flight
traces (.igc files) and scoring information (.xml) for each contestant. These
.zip files can then be put on a web page where Internet users can view a replay
of the contestant's flights for that day.

Andrej at Naviter writes:

I know winscore. It's been around for longer than SeeYou and I
know Guy as well. Americans have different rules and like to change them a lot
so have tended not to use SeeYou for scoring (yet). It's all good.

Of course, SeeYou was used at the 2012 World Championships in
Uvalde, Texas, see
here.