R, Matlab, Python, Mathematica, Gauss, and Julia use C libs. --Ilya
As a C lib, you have the possibility of not initializing the runtime, which leaves usable a part of phobos+druntime and it's only a matter of avoiding TLS/globals and global ctor/dtor. No need to rewrite druntime this way.
https://www.auburnsounds.com/blog/2016-11-10_Running-D-without-its-runtime.html -betterC is cleaner (link errors) but give more work.
