Text Widget and Link with I18n

Translation of a text widget (and your whole site) should be handled by a multilingual plugin. They each have their own way of doing it.

First, you need to prepare it for internationalization using:
_e("Rules...",'ehmm?')

You then need to create a .po file and translate the string yourself. The language is determined by wp_lang inside of wp_config.php

Thanks.
At the end I have done a simple plugin with my widget and use the wp-plugin internationalization.