FxParlant Wrote: ...
Does anybody knows if there is a simpler way of doing this. I 've heard a lot of interwiki language, is it applied to change the interface from visitor to visitor?
To force the interface language temporarily, for one page, you can use uselang=fr in the URL. To use an auto-detected language for anonymous users, you want to set the default language for anonyoumouse users depending on their browser's Accept-Language header. See bug 3665 http://bugzilla.wikimedia.org/show_bug.cgi?id=3665.
HTH -- Daniel