A google search reveals this slashdot story yielding this github repository that hasn't had a commit since 2016. There are 22,602 forks listed on github.com but these are going to be mostly (if not virtually all) simply development forks for torvalds/linux.
What prompts this question was this article on LWN discussing attempts to compile Linux with clang. I've read that the kernel uses many quirks/special features specific to gcc for optimization (though the linked article seems to downplay them compared to my memory), and I began to wonder if anyone had attempted to refactor/fork the kernel to make it more portable, or at least compilable outside of the gnu-environment. I also understand that gcc iteself is crufty, and Linus himself has criticized it.
I know I am not alone in my personal distaste for RMS and GNU and interest in Linux devoid of GNU; I am aware of Alpine Linux which does without gnu tools, but the kernel is still compiled with gcc, isn't it? There are many references to alternative toolchains and userland software, but I am specifically wondering about the kernel and whether there are forks that eliminate gcc/gnu dependencies--consider this a subsidiary question of the title--it seems to me it would be a waste to ask it separately.