You can't easily add a new filesystem or screw with the kernel on macOS/windows without having to buy hundreds of dollars worth of their books and attend conferences.
There isn't really any good detailed up to date documentation online about either.
That's not true, at least for Windows. MS has published a lot of docs on their site, e.g.:
There isn't really any good detailed up to date documentation online about either.
That's not true, at least for Windows. MS has published a lot of docs on their site, e.g.:
https://learn.microsoft.com/en-us/windows-hardware/drivers/i...
What does get in the way with newer versions of Windows is driver signing, but that's not a huge obstacle.