NetBSD

NetBSD is an open-source, Unix-like operating system that descends from Berkeley Software Distribution (BSD), a Research Unix derivative developed at the University of California, Berkeley. It was the second open-source BSD descendant formally released after it forked from the 386BSD branch of the BSD source-code repository. It continues to be actively developed and is available for many platforms, including large-scale server systems, desktop systems, and handheld devices, and is often used in embedded systems.