NetBSD is a free and 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. The NetBSD project focuses on code clarity, careful design, and portability across many computer architectures. NetBSD's source code is openly available and permissively licensed.