Swahili is a language spoken in Eastern Africa, Afrikaans is spoken in South Africa and Namibia, Yiddish has 3 million speakers in the Orthodox Jewish communities, Malay is an official language in Brunei, Malaysia, and Singapore. Welsh is spoken in Wales, England and Argentina, Irish is spoken by a small minority of the Irish population, Macedonian has less than 3 million speakers and many enemies, while Belarusian has 9 million speakers.
The number of languages supported by Google Translate is 51, which is impressive, but there are still many popular languages that aren't supported. At least not yet.
{ via John Mueller }