Recently, Guillaume Glairon-Mondet made the first repeat of Jan Hojer's Le Marathon de Boissy, ~8C, at Boissy aux Cailles, Fontainebleau. Now there is a video.
This problem traverses in from the left to Le Arête de Boissy assis, ~8B+, and according to Guillaume, it requires power endurance as well...
Read more at http://www.ukclimbing.com/news/item.php?id=69421