Haiku – open source operating system
Quoting: Haiku - open source operating system - LinuxLinks —
Haiku is an open-source operating system that specifically targets personal computing. Inspired by the Be Operating System (BeOS), Haiku aims to be fast, simple to use, easy to learn and yet very powerful.
Haiku is not a Linux distribution, nor does it use the Linux kernel. Haiku is the spiritual successor to BeOS and it is derived from the NewOS kernel, which was authored by Travis Geiselbrecht (geist), who was formerly employed by Be Inc. — the developers of BeOS.