>threw their weight behind the Linux kernel (or if GNU is too restrictive The GPL isn't too restrictive. Google has no issue with it on Android (which uses a

>threw their weight behind the Linux kernel (or if GNU is too restrictive The GPL isn't too restrictive. Google has no issue with it on Android (which uses a modified Linux kernel). GPL doesn't mean you have to open-source everything, just the GPL components, which in the case of the Linux kernel, is just the kernel itself. MS already contributes a bunch of drivers (for their hypervisor) to the Linux kernel. They could easily make a Linux-based OS with their own proprietary crap on top if they wanted to. >support for Android apps without emulation They wouldn't need CPU-level emulation, but the API would need some kind of compatibility layer, similar to how WINE serves this purpose for Windows applications on Linux. >Microsoft could build Windows on top of that POSIX kernel and provide a compatibility layer for NT calls and Win32 APIs. They don't need to: they can just use WINE. They could improve that, or maybe fork it and add some proprietary parts like CodeWeavers does, or they could even just buy out CodeWeavers.