The focus of this category is on the family of Unix-like operating systems that stemmed from the Berkeley Software Distribution (BSD), a now-discontinued OS based on Research Unix.
Unix was an early operating system developed by AT&T and Bell Labs in the late 1960s and early 1970s. Although Unix would later become proprietary and expensive, the earliest versions of the OS included the source code, allowing researchers to modify and extend the system.
These versions are known as Research Unix and, starting with the 8th edition, versions of Research Unix had a close relationship to BSD. Developed at Berkeley, BSD was used as the basis for the 8th edition of Unix.
The first versions of BSD used proprietary AT&T Unix code and were subject to the AT&T software license. By then, source code licenses had become very expensive, and there was a growing interest in a separate release of code, to be developed outside of AT&T and not subject to its licensing requirements. The result was Networking Release 1 (Net/1), released in 1989, which was freely distributable under the terms of the BSD License.
With all of the AT&T code replaced by 1991, Net/2 was a nearly complete OS that was freely distributable. A lawsuit was filed by AT&T's Unix System Laboratories, but it was settled in BSD's favor.
Net/2 became the basis of a proprietary and a free port to the 80386 architecture. One became BSD/386, while the other was initial codebase for NetBSD and FreeBSD.
Development of BSD at Berkeley was discontinued after a 1995 release. Since then, several variants have been based on the BSD code, including FreeBSD, NetBSD, OpenBSD, and DragonFly BSD. The permissive nature of BSD licensure has allowed several other operating systems to incorporate portions of the BSD code, parts of which were incorporated into Microsoft Windows, Apple's macOS and iOS, and Solaris, although these operating systems are not generally considered to be part of the BSD family.
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Inspired by MikeOS, and written in assembly language, BareMetal was created by Return Infinity, which continues to be responsible for its development. Available under the terms of the BSD License, BareMetal is an exokernel-based single address space operating system designed to be used in virtualized environments for cloud computing. A brief history of the project is told on its site, along with the advantages of the OS, the developer’s goals, and other information.
http://www.returninfinity.com/
Forked from FreeBSD in 2003, Dragonfly has since diverged significantly from FreeBSD, particularly in its implementation of lightweight kernel threads, an in-kernel message passing system, and the HAMMER file system, including some design concepts from AmigaOS. A history of its development is told here, and its features are listed, along with performance information, screenshots, and documentation. It may be downloaded freely, under the terms of a BSD License.
http://www.dragonflybsd.org/
Maintained by the FreeBSD Project, FreeBSD is a free and open-source Unix-like operating system, based on the Berkeley Software Distribution (BSD), which was itself based on Research Unix. Although BSD has similarities to Linux, although FreeBSD maintains a complete system, consisting of a kernel, device drivers, user-space utilities, and documentation, whereas Linux has only a kernel and drivers. FreeBSD is available under the FreeBSD License.
https://www.freebsd.org/
Based on FreeBSD, GhostBSD offers the benefits of FreeBSD with a focus on simplicity for newcomers. The OS ships with a simple installer, with preinstalled MATE or XFCE desktop environments, and a graphical application to install software and updates to the system. With modest hardware requirements, it is suitable for modern workstations and single-board 64-bit computer hardware. It is available under the terms of the Revised BSD License, although it contains GNU GPL software.
http://www.ghostbsd.org/
The free and open-source (CDDL, BSD, MIT) operating system is Unix-like, and based on OpenSolaris, which was itself based on System V Release 4 and the Berkeley Software Distribution (BSD). Created in 2010, Illumos is developed by the Illumos Foundation, which includes volunteers and companies. Illumos distributions include OmniOS and OpenIndiana, which can be installed on a hard drive or in a virtual machine. A community forum is included.
https://illumos.org/
Forked from FreeBSD in 2005, MidnightBSD is a free and open-source (FreeBSD License), Unix-like, desktop operating system that uses GNUStep as its default desktop environment. Preinstalled with the OS are applications for email, web browsing, word processing, gaming, and others. A history of the OS is put forth, and its features are highlighted, along with release notes, mirror status, and an application store. Developer resources and a user forum are included.
http://www.midnightbsd.org/
Created at VU Amsterdam, Minix is a free, open-source (BSD) operating system designed to be reliable, flexible, and secure. Originally proprietary, it was relicensed under the BSD License in 2000. Released in 1987, Minix is Unix-like and POSIX-compliant. Its features are highlighted on its site, which also includes documentation, a FAQ, and other resources for those who are new to the OS, such as a guide to getting started. Links to other user-supported websites are included.
http://www.minix3.org/
Developed by the NetBSD Project, NetBSD is a free and open-source (2-clause BSD License) based on the Berkeley Software Distribution (BSD) OS. Released in 1993, it was the first open-source BSD descendant released after 386BSD was forked, and continues to be actively developed. Available for several platforms, including servers, desktops, handheld devices, and embedded systems, portability was a central design goal. Its site includes download links, documentation, user and developer support.
http://www.netbsd.org/
Created as a fork of NetBSD in 1996, OpenBSD is a free, multi-platform BSD-based, Unix-like operating system with an emphasis on portability, standardization, correctness, proactive security, and integrated cryptography. Developed entirely by volunteers in the OpenBSD Project, its project goals are spelled out on its site, supported hardware systems are listed, and information about its security features are posted. Commercial support is available, as well as user groups.
http://www.openbsd.org/
