The BSD or Berkeley Software Distribution family of operating systems are derivatives of Unix that were once developed at the Computer Science Research Group at the University of California, Berkeley during the 70s, 80s, and 90s, building atop the UNIX v6 and UNIX 32/V releases from Bell Labs. In the late 80s and early 90s the CSRG worked on replacing encumbered AT&T code with their own and released Net/2. The release by BSDI of BSD/386 led to a lawsuit from AT&T as they claimed that Net/2 still contained AT&T code but was sold to those without AT&T licences. Out of the settlement of the lawsuit came the CSRG's last release, 4.4BSD-Lite, from which modern BSD systems are based upon (along with 386BSD).
As a result of the permissive and simple BSD Licence (see Licenses), the BSDs frequently see their work incorporated in other systems. For example, Windows NT 3.1 used the Berkeley TCP/IP stack, and Juniper Networks hardware uses a derivative of BSD called JunOS. BSD was where the vi editor was first developed and released.
There are many BSD operating systems in use today:
- FreeBSD, built for general purpose use, found for example in the PlayStation 4.
- OpenBSD, acclaimed for it's security principles and outspoken head developer Theo de Raadt.
- NetBSD, built for high portability to as many platforms and architectures as possible.
- DragonflyBSD, a fork of FreeBSD that introduces a new multiprocessing paradigm and the HAMMER file system while being suitable for desktop use and attempting to revive the spirit of AmigaOS for the 21st century.
- TrueOS (formerly PC-BSD), a derivative of FreeBSD that is designed as a friendly and easy to use desktop operating system based on KDE.
- MidnightBSD, another fork of FreeBSD that uses the Etoile/GNUstep environment that is similar to NeXTSTEP.
- GhostBSD, yet another fork of FreeBSD, combined with MATE desktop environment and a focus on user-friendliness.
- OS X (more specifically Darwin), the proprietary operating system from Apple used on Macintosh computers that has a distant relationship to FreeBSD.