[hountsi]

I would like to find some book in my langage
Sometime word is same in french and english
I would like to filter search for having only answer from computer with french interface

[Link64]

Besides the fact, that it would not be possible without probably quite major changes in Kad (the GUI language of the publishing client would have to be published together with every keyword and file causing also a lot of overhead), what makes you sure, that people sharing french stuff actually use french GUI? For the first, french might not be their first language, and secondly, even if it is, they still don't need to use eMule in french or even french operating system on their computer.