Dungan is a Sinitic language spoken by the descendants of Hui (Muslim) refugees who fled from northwest China after a failed revolt against the Qing (Manchu) government about a century and a half ago. Experiencing horrible losses along the way, their remnants settled in parts of what are now Kazakhstan and Kyrgyzstan, where ultimately they thrived and are quite successful today, particularly in growing produce.
Naturally, separated as they were from their homeland and its speech community, the language of the Dungans has undergone considerable change, especially through the borrowing of terms from Russian, Persian, Arabic, Turkic, and other languages. Even more radical was the adoption of the Cyrillic alphabet for their writing system (nearly all of those who fled were illiterate in Chinese characters).
For a brief introduction to the Dungans and their language, see "Dungan: a Sinitic language written with the Cyrillic alphabet".
For those who want to hear what Dungan sounds like, there is now an excellent opportunity, since the movie "Jesus" has been dubbed into Dungan. For someone who knows Modern Standard Mandarin (MSM), it's amazing to listen to — sometimes partially understandable, sometimes dramatically affected by Turkic and Russian. Though it's usually considered to be a variety of Mandarin, unless one is a native speaker of northwest Mandarin, it's very hard to pick out much of what is being said (much less what is written in Cyrllic). Since the language has diverged so much from what it was a hundred and fifty years ago, I suspect that it is hard to follow even for contemporary northwest Mandarin speakers.
Here's the film:
I'll be interested in hearing your reactions, especially those of you who know MSM to some extent, whether you're fluent or just a beginner. If anyone is actually from the areas of northwest China whence the Dungans fled about a hundred and fifty years ago, I'd be particularly eager to hear your reactions to the speech of modern Dungans as presented in this film. Incidentally, "Jesus" is available in more than 1,100 languages.
[Hat tip Leopold Eisenlohr]