Are there any (programming) languages who's important libraries have solid documentation/tutorial coverage in non-english languages? Honest question. Those are a big part of programming for me.
Yep. Ruby springs to mind. The creator, Yukihiro Matsumoto ("Matz"), is Japanese. He co-wrote the first Ruby book, which was in Japanese. And a year later, he co-wrote the first book for Ruby that was in English.