Chimera – a Linux that isn't GNU/Linux • The Register
Chimera Linux is an existence proof that this is not a hard requirement: it avoids all of these. Chimera is compiled with LLVM, uses the same musl C library and packaging tools as the lightweight Alpine Linux distro, the new Dinit init system, and much of the rest of the userland is drawn from the current version of FreeBSD. If things go according to plan, Kolesa hopes to release the first alpha version around the same time as the planned FreeBSD version 13.2, so that he can rebase on that version of the underlying tools.
Kolesa's talk is recommended, but be warned, it's very technical. For a quick overview, you can read his presentation (PDF).