SmartOS
SmartOS is an open-source UNIX-like operating system based on illumos, a community fork of OpenSolaris. It features four technologies - ZFS (a combined file system and logical volume manager), DTrace (a dynamic tracing framework for troubleshooting kernel and application problems), Zones (a lightweight virtualisation solution), KVM and bhyve (two full virtualisation solutions for running a variety of guest operating systems, including Linux, Windows, BSD and Plan9).
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.