BSDs

There are a number of Unix-like operating systems under active development, descended from the Berkeley Software Distribution (BSD) series of UNIX variants developed (originally by Bill Joy) at the University of California, Berkeley Electrical Engineering and Computer Science department. As of 2016^[update] there were four major BSD operating systems, and an increasing number of other OSs derived from these, that add or remove certain features but generally remain compatible with their originating OS—and so are not really forks of them. This is a list of those that have been active since 2014, and their websites.

FreeBSD is a free Unix-like operating system descended from AT&T UNIX via the Berkeley Software Distribution (BSD). FreeBSD currently has more than 200 active developers and thousands of contributors. Other notable derivatives include DragonFly BSD, which was forked from FreeBSD 4.8, and Apple Inc.'s Mac OS X, with its Darwin base including a large amount of code derived from FreeBSD.

NetBSD is a freely redistributable, open source version of the Unix-derivative Berkeley Software Distribution (BSD) computer operating system. It was the second open source BSD descendant to be formally released, after 386BSD, and continues to be actively developed. Noted for its portability and quality of design and implementation, it is often used in embedded systems and as a starting point for the porting of other operating systems to new computer architectures.

OpenBSD is a Unix-like computer operating system descended from Berkeley Software Distribution (BSD), a Unix derivative developed at the University of California, Berkeley. It was forked from NetBSD in 1995. OpenBSD includes a number of security features absent or optional in other operating systems and has a tradition of developers auditing the source code for software bugs and security problems.

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