The first version was released in 1993 developed from 386BSD[3]—the first fully functional and free Unix clone—and has since continuously been the most commonly used BSD-derived operating system.

[7] The FreeBSD source code is generally released under a permissive BSD license, as opposed to the copyleft GPL used by Linux.

[citation needed] In 1974, Professor Bob Fabry of the University of California, Berkeley, acquired a Unix source license from AT&T.

[16] In 1992, several months after the release of Net-2, William and Lynne Jolitz wrote replacements for the six AT&T files, ported BSD to Intel 80386-based microprocessors, and called their new operating system 386BSD.

[16] The development flow of 386BSD was slow, and after a period of neglect, a group of 386BSD users including Nate Williams, Rod Grimes and Jordan Hubbard[17] decided to branch out on their own so that they could keep the operating system up to date.

[19][16] In the early days of the project's inception, a company named Walnut Creek CDROM, upon the suggestion of the two FreeBSD developers, agreed to release the operating system on CD-ROM.

[26] Netflix,[27] WhatsApp,[28] and FlightAware[29] are also examples of large, successful and heavily network-oriented companies which are running FreeBSD.

[23] In January 1992, Berkeley Software Design Inc. (BSDi) started to release BSD/386, later called BSD/OS, an operating system similar to FreeBSD and based on 4.3BSD Net/2.

[32] A number of desktop environments such as Lumina, GNOME, KDE, and Xfce, as well as lightweight window managers such as Openbox, Fluxbox, dwm, and bspwm, are also available for FreeBSD.

Soft updates can protect the consistency of the UFS filesystem (widely used on the BSDs) in the event of a system crash.

GEOM is a modular framework that provides RAID (levels 0, 1, 3 currently), full disk encryption, journaling, concatenation, caching, and access to network-backed storage.

[53] In November 2012, The FreeBSD Security Team announced that hackers gained unauthorized access on two of the project's servers.

Apparently hackers gained access to these servers by stealing SSH keys from one of the developers, not by exploiting a bug in the operating system itself.

[54][55][56] FreeBSD provides several security-related features including access-control lists (ACLs),[57] security event auditing, extended file system attributes, mandatory access controls (MAC)[58] and fine-grained capabilities.

The project was founded by Robert Watson with the goal of implementing concepts from the Common Criteria for Information Technology Security Evaluation and the Orange Book.

[65] As of December 2023[update], FreeBSD has been ported to the following architectures:[35] The 32-bit ARM (including OTG) and MIPS support is mostly aimed at embedded systems (ARM64 is also aimed at servers[67]), however FreeBSD/ARM runs on a number of single-board computers, including the BeagleBone Black, Raspberry Pi[68][69] and Wandboard.

Applications may either be compiled from source ("ports"), provided their licensing terms allow this, or downloaded as precompiled binaries ("packages").

[76] Ports use Makefiles to automatically fetch the desired application's source code, either from a local or remote repository, unpack it on the system, apply patches to it and compile it.

[7][77] Depending on the size of the source code, compiling can take a long time, but it gives the user more control over the process and its result.

[82][83][84] For comparison, bhyve is a similar technology to KVM whereas jails are closer to LXC containers or Solaris Zones.

FreeBSD's kernel provides support for some essential tasks such as managing processes, communication, booting and filesystems.

It uses a text user interface, and is divided into a number of menus and screens that can be used to configure and control the installation process.

BSDcon is not FreeBSD-specific so it deals with the technical aspects of all BSD-derived operating systems, including OpenBSD and NetBSD.

[112] In addition to BSDcon, three other annual conferences, EuroBSDCon, AsiaBSDCon and BSDCan take place in Europe, Japan and Canada respectively.

If a feature is sufficiently stable and mature it will likely be backported (MFC or Merge from CURRENT in FreeBSD developer slang) to the -STABLE branch.

Beastie first appeared in 1976 on Unix T-shirts of comic artist Phil Foglio art,[127] for Mike O'Brien,[128][129][130][131] with some purchased by Bell Labs.

[135] In lithographic terms, the Lasseter graphic is not line art and often requires a screened, four-color photo offset printing process for faithful reproduction on physical surfaces such as paper.

Because of these worries, a competition was held and a new logo designed by Anton K. Gural, still echoing the BSD daemon, was released on 8 October 2005.

This can be compared with Linux distributions, which are all binary compatible because they use the same kernel and also use the same basic tools, compilers, and libraries while coming with different applications, configurations, and branding.

Darwin, the core of Apple's macOS, includes a virtual file system and network stack derived from those of FreeBSD, and components of its userspace are also FreeBSD-derived.