Huawei? I don’t know of any write-ups, but basically

There is a HongMengOS (Harmony OS) that’s a microkernel for embedded systems, there is also another OS by the same name that’s basically We Have Android At Home™, they have their own app store and their own app SDK that last time I checked, you needed to submit your real life gover ID and credentials to be able to download.

Imagine that, you want to develop an app and you need to give your full legal detail to Huawei for review and after you’re manually cleared you can be bestowed the permission of downloading the fucking IDE