1. Linux is Unix, as it's POSIX compilant and mostly follows Unix tradition, style and feel.
2. GNU/Linux is Unix.
3. I call it just Linux, which is the kernel, i.e. essential part of the OS, and when I want to be more specific, I mention the distribution. I'll do this regardless of if the GNU guys want it called GNU/Linux for including GNU tools, the vim guy wants it called vim/Linux for including vim, and id Software wants it called Quake3/Linux if you install Quake 3.
>>45
You can replace anything by propietary software without violating the GPL. You only cannot distribute it. GPL does not restrict use, it restricts distribution.
BTW, the day Hurd comes out, I'll call it Hurd, not GNU/Hurd, tee hee.