FreeBSD

FreeBSD is a free and open-source Unix-like operating system that comes from the Berkeley Software Distribution, a version of Unix made at the University of California, Berkeley. It started in 1993 and released its first version, FreeBSD 1.0, the same year. This operating system includes everything needed to run a computer, like the main part (kernel), drivers for devices, tools for users, and lots of helpful guides.

FreeBSD is especially good for running servers, networking, storing data, and powering small devices. It has strong features for connecting computers together, keeping information safe, and making it easy to add extra programs. Many important services use FreeBSD, such as the Netflix Open Connect system that helps deliver videos quickly and the pfSense software for creating secure firewalls and routers.

The group behind FreeBSD is led by people who are chosen by others in the project, and there is also a foundation that helps with support and legal issues. Parts of FreeBSD have been used in many other operating systems, including the base for macOS, iOS, iPadOS, watchOS, and tvOS, as well as in systems for PlayStation 3, PlayStation 4, PlayStation 5, and PlayStation Vita game consoles.

Today, the newest version is FreeBSD 15, which came out on 2 December 2025. The older version, FreeBSD 14, is still supported, with its latest update on 10 March 2026. The code for FreeBSD is shared under a license that lets anyone use it freely, either for open-source projects or for products that are not open to everyone.

History

Berkeley Unix and 386BSD background

FreeBSD is part of a group of operating systems called BSD that started at the University of California, Berkeley. In 1974, a teacher there got permission to use a version of Unix and began changing it to work better. He added important features like a way for computers to talk to each other over networks. At first, these changes needed special permission to share, but in 1989, the first public version was released.

A man named Keith Bostic led a project to remove the parts that needed special permission. After about a year and a half, almost all of the special parts were gone, and more people could use and share the system freely.

Creation

The FreeBSD Project started in early 1993 by a few people who were helping others fix and update another system called 386BSD. The name "FreeBSD" was chosen in June 1993. The first full version, FreeBSD 1.0, came out in December 1993. It was built using parts from Berkeley's work and other free software.

A company called Walnut Creek CDROM helped a lot by putting FreeBSD on CD-ROMs and supporting the project. They also helped pay for things the project needed.

Lawsuit

In 1992, a company called Berkeley Software Design began selling its own version of the system. AT&T, the original creator of Unix, sued them for sharing some of their code without permission. The lawsuit was settled, and the companies agreed to use newer, freer code. Even though FreeBSD wasn't part of the lawsuit, they also switched to this newer code. By FreeBSD 2.0 in 1994, there was no code left from AT&T.

Growth and current situation

In the late 1990s and early 2000s, FreeBSD became very popular for use on internet servers and network devices. It was known for being stable and working well for networks. Newer versions added many useful features.

Big companies like IBM, Nokia, Juniper Networks, and NetApp use FreeBSD in their products. Parts of Apple's macOS and the software for PlayStation 3, PlayStation 4, and Nintendo Switch also use code from FreeBSD. Companies like Netflix, WhatsApp, and FlightAware use FreeBSD to keep their systems running.

FreeBSD 15.0 was released on December 2, 2025. This version included many new features and was available for several types of computer processors.

Features

Complete operating-system model

FreeBSD is built as a full operating system, not just a kernel. It includes everything needed to run a computer: the kernel, drivers, system tools, and documentation all in one place. This makes it different from many Linux systems, which combine their kernel with tools from many different sources.

Use cases

FreeBSD can be set up to perform many different jobs, like a mail server, web server, firewall, FTP server, DNS server or router. It can also be used on everyday computers like desktops or laptops. While it doesn’t include a graphical interface by default, many popular interfaces are available to choose from.

Networking

FreeBSD has always been strong in networking. It uses a reliable method for sending information over the internet and supports modern features like IPv6 and secure connections. FreeBSD includes several tools to manage network traffic and protect systems.

Storage and filesystems

FreeBSD offers various ways to store and protect data. It includes tools to keep files safe even if the system turns off suddenly and supports different methods for organizing storage space.

Security

FreeBSD includes several features to keep the system secure, such as controlling who can access files and tools for monitoring system activity. The project has a team that looks for and fixes security issues.

Portability and platforms

FreeBSD can run on many different types of computer processors. The project organizes support for these processors into levels, with some being fully supported and others still under development.

Hardware compatibility

FreeBSD can work with many different devices and computers. There is a list of known compatible hardware, and community projects help collect information about what works well.

Third-party software

FreeBSD allows users to add extra programs beyond the basic system. These programs can be added easily using pre-built packages or built from source code.

Jails

FreeBSD jails are a way to run separate environments within the main system. This helps isolate different tasks and keeps the system organized.

Virtualization

FreeBSD supports running other operating systems inside it using a tool called bhyve. This allows users to test or use different systems without needing separate computers.

OS compatibility layers

FreeBSD can run programs made for other operating systems, like Linux, by translating their commands. This makes it easier to use software made for other platforms.

Kernel

FreeBSD’s kernel is all-in-one and includes many features like managing processes, memory, and devices. It can load and unload parts as needed, making it flexible.

Documentation and support

FreeBSD has extensive documentation, including guides, FAQs, and archives of questions and answers. This helps users learn how to use the system and solve problems.

Installers

FreeBSD used a text-based installer for many years, but now uses a simpler installer that is easier to use.

Shell

FreeBSD normally uses a simple shell for commands. Other shells are available for users who prefer them.

Development

The FreeBSD Project is built by a group of people working together online. Many of these developers have never met each other in person. They hold special meetings each year to talk about their work.

There are about 500 developers who help shape FreeBSD. They work on different parts of the system, like tools, guides, and safety checks. A group called the Core Team is chosen every two years to help guide the project. Other helpers can suggest changes, and if their ideas are good, they might get to join the team of developers.

FreeBSD has different versions that change over time. One version is always being updated with new features, while another is kept stable for safety. Each major version gets updates for four years to keep it secure.

The FreeBSD Foundation is a group that helps support the project. It gives money for development, supports tools, and helps teach people about FreeBSD. In 2014, it received a big donation to help with its work.

Licensing

FreeBSD is shared under special rules that make it easy for anyone to use. Most of the software in FreeBSD uses a simple license called BSD-2-Clause. This means you can use, change, and share the software freely. Some parts of FreeBSD use other open rules, like CDDL, GPL, or ISC, but these are used carefully.

The FreeBSD team prefers using the BSD-2-Clause license for new additions. They keep different types of licenses separate so that companies can make products with just the simple licenses. They also worked on replacing an old tool with a new one that fits their license rules.

Free Software Foundation
Open Source Initiative
GCC
LLVM
Clang

Logo

For many years, FreeBSD was linked with a special figure called the BSD Daemon, often named Beastie. This friendly figure was first shown in 1976 on special computer shirts made by Phil Foglio. Later, famous animator John Lasseter made more versions of Beastie.

Because these pictures did not look good when made small or in black and white, FreeBSD asked artists to design a new logo. The logo we use today was made by Anton K. Gural and shared on October 8, 2005. Robert Watson said they were looking for a new logo but would keep Beastie as the friendly face of the project. The words "The Power to Serve" are a special sign used by the FreeBSD Foundation.

Derivatives

Further information: List of products based on FreeBSD

Many systems and products are built using FreeBSD. They often have small changes and extra software to suit different needs, much like how different versions of a popular game might have special features.

Some examples include Juniper's JUNOS for routers, Isilon's OneFS for storage, NetApp's Data ONTAP 8, and Netflix's Open Connect appliances. The software for the PlayStation 4 ("Orbis OS") comes from FreeBSD 9, and the PlayStation 5 also uses FreeBSD as a base.

DragonFly BSD is a separate system created from an older version of FreeBSD. It was made to try new ways of handling many tasks at once. Darwin, which is part of Apple's macOS, uses ideas from FreeBSD for how it handles files and connections. Chimera Linux mixes the Linux system with parts from FreeBSD to make something new.

Version history