You can write your library in any language you want, with the single condition that you '''cannot''' use C/C++/Java and '''must''' choose . Consider choosing a language you don't usually use , or have never used beforeand want to learn. Challenge yourself to learn something new, and push yourself out of your comfort zone. You aren't being marked on the quality of your code, this is just a learning exercise. Here are some suggestions:

* JavaScript (or TypeScript) and node.js* TypeScript (a version of JS with static types)