Is Chomsky's X bar theory applicable to any natural language other than English? Or is it applicable to English only or to only a subset of natural languages including English?
EDIT
I think that the X-bar theory in its default version describes the English language. If so, I wonder if there have been any efforts of either Chomsky himself or some other linguists to assign a different version with a set of different rules to another language than English, such as French, German, Chinese, Japanese, Korean, etc.