Every viewer can edit his personal language settings in his profile menu under “Languages”.

Here you can choose the language of your user interface.
Out of the box, Phonemos supports currently:
English
French
German
French
Adding a new UI language is actually rather simple for most languages, but as it will need to be maintained with every new versions, we add new language versions on demand. Just reach out to us to request a new UI language version.
Please note that changing the language of the user interface does not change the language of the content. See Multi-lingual page versions for more information on translating content.