In principle, MetaTexis can be run in (almost) all languages of the world. You can choose the language you prefer via the Menu language drop-down box. It includes all languages available on your system. Two languages are available on any system because they are built-in: English and German.
How many additional languages are available depends on the number of language files in the MetaTexis language directory. The language directory is the "LanguageFiles" sub-directory in the MetaTexis program directory (see About MetaTexis).
To add a language to MetaTexis, simply copy a language file into the language directory. All official language files are available at the MetaTexis homepage (www.metatexis.com).
If your preferred language is not available, you can make your own language file. For further instructions, see Localization.