List of BSD operating systems
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 EECS department. Currently, there are 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 in the last couple of years, and their respective 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.
|DragonFly BSD||Originally forked from FreeBSD 4.8, now developed in a different direction|
|DesktopBSD||DesktopBSD is a Unix-derivative, desktop-oriented operating system based on FreeBSD. Its goal is to combine the stability of FreeBSD with the ease-of-use of KDE, which is the default graphical user interface.|
|Evoke||Formerly DamnSmallBSD; a small live FreeBSD environment geared toward developers and system administrators.|
|Frenzy Live CD||A "portable system administrator toolkit". It generally contains software for hardware tests, file system check, security check and network setup and analysis.|
|Gentoo/FreeBSD||Gentoo/*BSD subproject to port Gentoo features such as Portage to the FreeBSD operating system|
|GhostBSD||A GNOME-based, desktop FreeBSD distribution for x86 CPUs. Offers LiveCD/LiveDVD, and hard disk installation.|
|IronPort AsyncOS||security appliances|
|JunOS||For Juniper routers|
|MaheshaBSD||A LiveCD or USB stick-based modular toolkit, including an anonymous surfing capability using Tor. The author also made NetBSD LiveUSB - MaheshaNetBSD, and DragonFlyBSD LiveUSB - MaheshaDragonFlyBSD. A LiveCD can be made from all these USB distributions by running the /makeiso script in the root directory.|
|m0n0wall||m0n0wall is an embedded firewall distribution of FreeBSD, one of the BSD operating system descendants. It provides a small image which can be put on Compact Flash cards as well as on CDROMs and hard disks. It runs on a number of embedded platforms and generic PCs.|
|MidnightBSD||Midnight BSD has now forked away from FreeBSD 6.1 Beta|
|Nokia IPSO||Nokia IP security appliances|
|Paxym||FreeBSD for Cavium Networks OCTEON|
|PC-BSD||PC-BSD is a Unix-like, desktop-oriented operating system based on FreeBSD. It aims to be easy to install by using a graphical installation program, and easy and ready-to-use immediately by providing KDE as the default, pre-installed graphical user interface.|
|pfSense||pfSense is a FreeBSD-based firewall tailored for use as a firewall and router.|
|The Dark Star|
|Zrouter||FreeBSD based firmware for embedded devices|
DragonFly BSD-based 
|Gentoo/DragonFlyBSD||Gentoo/*BSD subproject to port Gentoo features such as Portage to the DragonFly BSD operating system|
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.
|BlackBSD||Live CD with security tools and Fluxbox.|
|Force10 Networks FTOS||the operating system for Force10 TeraScale E-Series switches/routers|
|Debian GNU/NetBSD||Debian GNU/NetBSD was a project to combine Debian with the kernel of NetBSD. It was abandoned in 2002 and has not seen active maintenance ever since.|
|Gentoo/NetBSD||Gentoo/*BSD subproject to port Gentoo features such as Portage to the NetBSD operating system.|
|Jibbed||Live CD based on NetBSD|
|PolyBSD / pocketSAN||Multipurpose framework for building embedded systems based on NetBSD.|
|SEOS||The operating system for the Ericsson SmartEdge router series|
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.
|ÆrieBSD||OpenBSD fork which tends to be free from GPL-licensed software.|
|adJ||Distribution of OpenBSD for spanish speakers, since 2007 new releases happen around 3 months after OpenBSD's releases, source in GitHub, to learn how to install there is a challenge with badge on P2PU|
|Bitrig||OpenBSD fork with main goal to be more modern in some aspects than OpenBSD.|
|BowlFish||a customized OpenBSD installation script for embedded systems, intended to make OpenBSD fit into small media like compact flash cards.|
|BSDanywhere||Live CD featuring the Enlightenment DR17 window manager|
|CD Bootable OpenBSD firewall|
|ComixWall||A firewall with UTM features|
|ekkoBSD||ekkoBSD was a Unix-like operating system based on OpenBSD 3.3, also incorporating code from other BSD-like operating systems. Its focus was on security and easy administration.|
|FuguIta||Providing both LiveCD and LiveUSB. Highly customizable by user. Tracking errata on OpenBSD-stable.|
|Gentoo/OpenBSD||Gentoo/*BSD subproject to port Gentoo features such as Portage to the OpenBSD operating system|
|JG Gimi's LiveCD|
|MarBSD||LiveCD of OpenBSD|
|MicroBSD||Fork of the UNIX-like BSD operating system descendant OpenBSD 3.0, begun in July 2002. The project's objective to produce a free and fully secure, complete system, but with a small footprint.|
|MirOS BSD||A secure operating system for 32-bit i386 and sparc systems based mostly on OpenBSD and some NetBSD, and utilizing the MirPorts Framework.|
|OliveBSD||Live CD originally based on OpenBSD 3.8|
|OpenBSD Live-CD Firewall|
|PsygNAT||Firewall and NAT router tool|
|Quetzal||Live DVD/CD system, based on OpenBSD|
|SONaFR||SONaFR is a small system with router/NAT/firewalling capabilities that fits on a single floppy.|
Historic BSD 
BSD was originally derived from Unix, using the complete source code for Sixth Edition Unix for the PDP-11 from Bell Labs as a starting point for the First Berkeley Software Distribution, or 1BSD. A series of updated versions for the PDP-11 followed (the 2.xBSD releases). A 32-bit version for the VAX platform was released as 3BSD, and the 4.xBSD series added many new features, including TCP/IP networking.
For many years, the primary developer and project leader was Bill Joy, who was a graduate student at the time; funding for this project was provided by DARPA. DARPA was interested in obtaining a programming platform and programmer's interface which would provide a robust, general purpose, time-sharing computing platform which would not become obsolete every time computing hardware was or is replaced. Such an operating system would allow Department of Defense software, especially for intricate, long-term finance and logistics operations, to be quickly ported to new hardware as it became available.
As time went on, code was later ported both from and to Unix System III and still later Unix System V. Unix System V Revision 4 (SVR4), released circa 1992, contained much code which was ported from BSD version up to and including 4.3BSD.