Welcome!
Mere Linux is a lightweight Linux distribution built around musl libc and s6 for system initialization and process supervision.
It also currently uses pacman for package management, busybox for a suite of core utilities, and llvm+clang as the main C compiler and toolchain.
Mere is under active development and is currently missing many features of a a typical Linux distribution. It is however, steadily progressing. You can monitor and contribute to its progress at https://github.com/jhuntwork/merelinux.