Hi Bastien, I copied index.org into ./ja directory with Japanese translation (not completed yet). The translation will be finished until this week end.
I made a branch "ja" in the orgweb repository for translation work. If this is not good for you and all, please let me know. By the way, do you have any solution to check the translated result in a browser (through HTTP)? HTML export from org files is a solution, but I'm not sure the layout and visual quality is correct. And also internal links between pages should be checked before pushing them into orgweb repository. Best, Takaaki Ishikawa