If you have version 5.3.0 of the XMLmind XML Editor, then you can download and install a Spanish 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 XXESpanishSetup.exe 527KB Run the installer. It will do all that is needed.
Mac OS X XXESpanish.dmg 405KB Run the installer. It will do all that is needed.
Linux XXESpanishSetup.tar.gz 390KB
  1. Decompress and extract the installer in some directory.
  2. In a Terminal, do 
    sudo ./installxxespanish