I've only really joined the D community and started programming it rather recently. So far, the most of the libraries I've seen are either D bindings to C & C++ programs, or tools related to the language itself. Of the ones that aren't, I've seen none that say anything about being used by other languages. In short, all the D libraries I'm aware of appear to be made specifically for use by D programs.
Of the libraries I know of that are often used outside the language they are written in, most are in C. All the one's that aren't are in C++.
But are there any exceptions that I should be aware of? Are there any libraries that have been written in D, and then gotten considerable use by programmers without D experience, in programs not written in D?
I would think that this would be technically viable with the betterC
option, though the difficulty would be in advertising it's compatibility to non-D programmers.