What it is probably not obvious to most people is that D has supports for D as better C, so it can have seamless interaction with C library and vice versa [1]. With betterC, D supports for C interfacing and integration is second to none. Heck, you can even compile the D compiler as a library if you fancy a built-in compiler for your C and D program. This seamless integration capability can be very productive where most of the high performance libraries are written in C.

[1]https://dlang.org/blog/2017/08/23/d-as-a-better-c/

[2]https://dlang.org/blog/2017/08/01/a-dub-case-study-compiling...