If you have version 5.3.0 of the XMLmind XML Editor, then you can download and install a French user interface and dictionary package.

To do so, download and install the package per your operating system:

Operating System Installer to download Size How to install
Windows XXEFrenchSetup.exe 915KB Run the installer. It will do all that is needed.
Mac OS X XXEFrench.dmg 787KB Run the installer. It will do all that is needed.
Linux XXEFrenchSetup.tar.gz 773KB
  1. Decompress and extract the installer in some directory.
  2. In a Terminal, do 
    sudo ./installxxefrench