https://code.fb.com/ai-research/unsupervised-machine-translation-a-novel-approach-to-provide-fast-accurate-translations-for-more-languages/

Automatic language translation is important to Facebook as a way to allow the billions of people who use our services to connect and communicate in their preferred language. To do this well, current machine translation (MT) systems require access to a considerable volume of translated text (e.g., pairs of the same text in both English and Spanish). As a result, MT currently works well only for the small subset of languages for which a volume of translations is readily available