But why? What benefit would that ultimately provide to the end user? Or are you just hoping that someone will magically conjure up a version of Windows that is completely free and somehow superior to Microsoft's offerings?Still Linux and OSX have open source kernels, Windows should too.
Except OS X and Linux still get reports of security vulnerabilities, and their users are probably a lot more enthusiastic about keeping their systems updated.There are ways they can mitigate the security nightmare that would cause as well. Give the sources to a well known group of people and have them go though the low hanging security issues and fix them for a while. Have a model where each vuln they fix they get payed or something and after a while it will be good enough to just put up on GitHub, a service that they own.
It's not possible to tear the ROM chip out of a DS cartridge and replace it with a different chip, is it? Or at least, it's certainly not usually done. It would be much easier to make some kind of clone with equivalent capabilities – except such a project is evidently not economically viable.The source code of Learn with Pokémon: Typing Adventure to be able to use the bluetooth inside the cartridge for other uses of ds homebrew.