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.
Talos Linux
Talos is a specialist Linux-based operating system for running Kubernetes, an open-source system for automating deployment, scaling and management of containerised applications. Minimal, immutable and hardened, it does not offer any shell or interactive console; instead, all system management is done via remote Application Programming Interface (API) calls, where messages sent from a client application are protected with mutual Transport Layer Security TLS (mTLS) authentication.