Ariadne allows you to create sites in multiple languages. It automatically keeps track of which page is available in which language, so you only see those pages you can read. Ariadne allows you to override this behaviour, showing all pages, even if not in your current language, when you need it to.
Ariadne handles things like switching languages, default languages, different site urls for different languages, etc. The selected language is always contained in the URL, either through specific site URLs or through a language code. This means that links to your site will always show the correct language.
Ariadne stores different language versions of a single page as a single object. This means you don't have to manually manage different versions of your site. All the information is shared, but not everything is shown. The Ariadne UI can be customized to only show those languages you are interested in, allowing you to focus on your part of the website.
Ariadne allows you to create language specific templates, this means that it is easy to support languages which don't follow the western top-to-bottom left-to-right conventions. You can create completely customized layouts for each language. Even files can be uploaded in many different languages and Ariadne makes sure the correct one is used.
Finally Ariadne stores all textual data as Unicode (UTF-8), which means you will never have to worry about character encoding. Ariadne can convert almost any character encoding to UTF-8 and back when you really need it.