Arch Linux
Arch Linux is an independently developed, x86_64-optimised Linux distribution targeted at competent Linux users. It uses 'pacman', its home-grown package manager, to provide updates to the latest software applications with full dependency tracking.
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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).