@Phosphenes >First you said Linux is proprietary then you linked to a Linux that is non-proprietary.
Yes, the Linux from kernel.org is proprietary, but GNU Linux-libre isn't.

>That's like saying 'Birds are blue' then pointing to a bunch of red birds.
More accurately I said saying that proprietary birds aren't blue and pointed to free blue birds (with proprietary red dye washed out) and then proprietary red birds.

>I mean, just provide some proof that the kernel is proprietary.
You seek and you shall receive:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/platforms/8xx/micropatch.c

That is software (MIPS instructions if I remember cpu-rec output correctly), without source code, nor an offer for source (looking at the git history, SPDX-License-Identifier: GPL-2.0 was slapped on by a script and isn't the license).

There's plenty more if you insist - I can go find my documentation as to all the proprietary software that I found.

>It might be more accurate to say 'some modules in some kernels are not free'.
Yes, so people have committed copyright infringement by writing proprietary Linux modules and distributing those, but thankfully that's becoming less common.