Kali Linux
Kali Linux (formerly known as BackTrack) is a Debian-based distribution with a collection of security and forensics tools. It features timely security updates, support for the ARM architecture, a choice of four popular desktop environments, and seamless upgrades to newer versions.
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).