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).
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FunOS
FunOS is an Ubuntu-based Linux distribution which features the JWM graphical user interface. The project is intended to be more lightweight than official Ubuntu community editions while providing the same application compatibility and hardware support.