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.
NebiOS
NebiOS is an Ubuntu-based desktop Linux distribution with a custom Wayland compositor called NebiDE (based on Wayfire). It features various user interface enhancements, an initial setup module called OOBE, the NebiOS App Runtime (napp-runtime) portable application format with bubblewrap containerization, improved gaming performance with Steam Proton integration, a kernel switcher for easy multi-kernel installation, and the Wine compatibility layer for running some Windows applications.