I wrote the implementation of the Nintendo Switch support. It currently uses the publicly available open source library Libnx and Devkitpro.

See https://github.com/switchbrew/libnx and my wrapper around that library (it has all functions exposed using nimgen, a C wrapping library, but the Nim-friendly wrapper is a WIP) https://github.com/jyapayne/nim-libnx

In order to use this, you must have a homebrew enabled Switch. Google is your friend!