Vanilla OS
Vanilla OS, a fixed-release distribution based on Debian (formerly Ubuntu, prior to version 2) with the GNOME desktop, is an immutable operating system. The core parts of the system are locked down to prevent unwanted changes and corruption from third-party applications or a faulty update.
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.