NixOS
NixOS is an independently developed GNU/Linux distribution that aims to improve the state of the art in system configuration management. In NixOS, the entire operating system, including the kernel, applications, system packages and configuration files, are built by the Nix package manager.
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AlmaLinux OS
AlmaLinux OS is an open-source, community-driven project that is built from the source code of Red Hat Enterprise Linux (RHEL). AlmaLinux is a completely binary compatible fork of RHEL and it is maintained by AlmaLinux OS Foundation which is a register non-profit.