Regarding GUI, there is also https://github.com/yglukhov/nimx which is based on OpenGL.
> Nimx officially supports Linux, MacOS, Windows, Android, iOS, Javascript (with Nim JS backend) and Asm.js/WebAssembly (with Nim C backend and Emscripten).
> Nimx officially supports Linux, MacOS, Windows, Android, iOS, Javascript (with Nim JS backend) and Asm.js/WebAssembly (with Nim C backend and Emscripten).