Only four hours later, German was already translated to a complete 100%! This is open source and we get a kick out of it! Thanks to Daniel Nemeth for translating!
On contao.org you'll find a "how to use Transifex".
The following languages would rejoice about some love:
Czech, Danish, Spanish, Persian, French, Italian, Dutch, Polish or Russian.
Of course we welcome any other language you speak! The project can be found here.