Every user can make his/her own version of MetaTexis, be it in a completely new language, not shipped with the original version, or be it a variant of an existing language.
There are two built-in languages: US English and German. These cannot be deleted or edited.
All other languages are stored in the "LanguageFiles" sub-directory of the MetaTexis program directory. To be recognized as a language file, a file must be a Unicode or ASCII text file, and it must have the extension ".lng".
(Although the ASCII format can be used, it is strongly recommend to use Unicode to make sure that the language file is correctly interpreted by every computer.)
If a language file with the correct format and the correct extension is copied into the language directory, it will be automatically recognized by MetaTexis (at the next startup of Word), and it will be added to the list of menu languages in the General options dialog box. There is no need to register language files.