OpenBSD

OpenBSD is a special kind of computer operating system that focuses on keeping things safe and secure. It was created in 1995 by Theo de Raadt, who started it by taking an existing system called NetBSD and making his own version. This new system was built to work well on many different types of computers and to do things the right way, with strong security built in from the start.

Because OpenBSD is free software, many other big companies use parts of it in their own products. For example, the safety features in Apple’s macOS computers, the basic tools in Android phones, and some important parts of Windows 10 all use ideas and code from OpenBSD. This shows how useful and reliable the system is.

The name “OpenBSD” tells us two important things: first, that anyone can see and use its code because it is available online, and second, that it works on many different kinds of hardware, from regular computers to newer types of processors. Even though it doesn’t have a fancy graphical interface by default, OpenBSD is powerful and trusted by people who care about keeping their computers safe.

History

In 1995, a person named Theo de Raadt started OpenBSD after leaving another project called NetBSD. He created OpenBSD to make a better and safer operating system. The first version was released in 1996, and since then, new versions have come out every six months.

In 2007, a group called the OpenBSD Foundation was created to help support the project. By 2024, OpenBSD had changed so much that none of the original files from NetBSD were left unchanged.

Usage statistics

It can be difficult to know how many people use OpenBSD because its developers do not keep track of user numbers.

In September 2005, a group asked 4,330 BSD users about their choices. About 32.8% said they used OpenBSD. More people used FreeBSD at 77%, while NetBSD was used by 16.3% and DragonFly BSD by 2.6%. The group that did the survey said their results might not be perfect because they shared the survey mostly with people already interested in BSD. This means it is hard to know exactly how many people use OpenBSD around the world.

Uses

OpenBSD has strong networking abilities and can work as a router or wireless access point. Its built-in cryptography and packet filter make it great for security tasks like firewalls, intrusion-detection systems, and VPN gateways.

Some versions of Microsoft's Windows Services for UNIX used code from OpenBSD. The pf firewall from OpenBSD is also used in FreeBSD and macOS. OpenBSD can be used on personal computers and includes many software packages like Firefox and Chromium.

OpenBSD can also be set up as a mail server, web server, FTP server, DNS server, router, firewall, NFS file server, or a mix of these. Starting with version 6.8, OpenBSD includes support for WireGuard directly in its software.

Security

See also: OpenBSD security features

After OpenBSD was created, its founder worked with a security company that made tools to find weak spots in software. This helped make security the main focus of OpenBSD.

OpenBSD has many features to keep it safe, like special tools to check for mistakes, ways to protect memory, and strong ways to keep information private. It also limits what programs can do to reduce risks. Developers often review the code to find and fix problems.

OpenBSD created a popular tool called OpenSSH, which helps computers talk to each other safely over the internet. The project believes in making computers simple and secure by default, so new users don’t have to worry about safety right away. Users can add more features themselves, thinking about safety first.

Subprojects

OpenBSD has helped create many useful tools and projects. Some of these include:

• bioctl, a tool to manage RAID similar to ifconfig
• CARP, a free tool to help computers work together, like Cisco's HSRP/VRRP
• cwm, a program to organize windows on your screen
• doas, a simpler way to give users special permissions instead of using sudo
• OpenBSD httpd, a web server program implementing httpd
• Game of Trees, a tool that works with Git
• hw.sensors, a system to monitor hardware sensors
• LibreSSL, a secure way to connect to the internet, created from OpenSSL 1.0.1g
• mandoc, a tool to format help pages called man pages
• OpenBGPD, a program for a special internet protocol called BGP-4
• OpenIKED, a program for IKEv2
• OpenNTPD, a simpler tool to keep time accurate
• OpenOSPFD, a program for a special internet protocol called OSPF
• OpenSMTPD, a mail server that works with IPv4/IPv6, PAM, Maildir, and virtual domains
• OpenSSH, a secure way to connect to other computers
• PF, a firewall for IPv4/IPv6 that includes NAT, PAT, QoS, and traffic normalization
• pfsync, a tool to keep PF working well with high availability using CARP
• rpki-client, a tool to help validate BGP announcements using the Resource Public Key Infrastructure (RPKI)
• sndio, a tool for audio and music
• spamd, a tool to block unwanted emails with greylisting
• Xenocara, a special setup of X.Org for better performance

Some of these tools are now used in other operating systems, and many can be added to other Unix-like systems as extra features.

The Calgary Internet Exchange began in 2012 to help support OpenBSD.

In 2017, a project called Isotop started, aiming to make OpenBSD easier to use on desktops and laptops using xfce and later dwm.

Third-party components

OpenBSD includes many tools and programs from other sources, often with special updates made just for OpenBSD. Some of these include X.Org for graphics, Clang as the main compiler for certain types of computers, GCC, Perl, NSD, Unbound, ncurses, GNU binutils, GDB, and AWK. These tools help users do many different tasks on the OpenBSD system.

Development

OpenBSD is always being improved, and anyone with the right skills can help. The leader, Theo de Raadt, helps organize the work. Every year, there are two big updates, and these updates are supported for a year. There are also smaller updates available more often.

People can update their OpenBSD systems in a few ways. They can use a tool called syspatch, update from a special area called CVS, or use another tool called sysupgrade to get the newest features. For most users, the basic OpenBSD kernel that comes with the system is the best choice.

Extra programs for OpenBSD are kept up to date by different people. These programs are built for each type of computer, and most people should use the ready-made versions instead of building them themselves. OpenBSD developers sometimes meet to work together and focus on getting things done. Many new versions of OpenBSD also have a special song.

Open source and open documentation

OpenBSD is well-known for its clear and helpful guides. When OpenBSD was started, its creator decided that anyone should be able to see the source code. At that time, only a few developers could usually see a project’s code. This team thought that was unfair and made it hard for new people to help. So, they created a public system where anyone could view and work with the code. This let users join more actively and showed OpenBSD’s promise to keep things open.

OpenBSD does not use secret code or parts that need special agreements to see. Because it comes from Canada, it can use strong security methods without rules from other countries. It also makes computer actions unpredictable to keep it safer. For example, it uses random numbers for different parts of the system. This helps find mistakes and makes it harder for bad people to attack. The project also believes in having clear information about hardware so developers can create better tools.

Closed source and proprietary code

OpenBSD sometimes includes small pieces of code that are not fully open. This is because some devices need special instructions to work, and these instructions are provided by the device makers.

The project leaders have to balance wanting to keep everything open while also making sure users can use many different devices with OpenBSD. They try to be practical and accept some risks when they include these special instructions.

According to the GNU Project, OpenBSD does include some small parts of code that are not fully open, called "blobs". These are used for device firmware or are needed by drivers that have open licenses.

Licensing

See also: Comparison of free and open-source software licenses and Free software license

OpenBSD has very careful rules about the kinds of licenses it uses. It prefers simple and open licenses like the ISC license and the BSD license. The project wants to keep the open spirit of the original Berkeley Unix, which allowed free sharing of its code. Some other popular licenses, like the Apache License and the GNU General Public License, are seen as too strict by OpenBSD.

In 2001, OpenBSD checked all its code to make sure every piece had the right license. They found many files without clear licenses or with rules that didn’t fit OpenBSD’s standards. To fix this, they contacted the original creators. Some code was removed, some was replaced, and some, like the multicast routing tools mrinfo and map-mbone, got new licenses so OpenBSD could keep using them. They also stopped using software made by Daniel J. Bernstein because he required approval for any changes, which OpenBSD couldn’t agree to.

Because of these license issues, OpenBSD sometimes builds its own tools instead of using others. For example, they created the PF packet filter after finding the rules for IPFilter too limiting. PF started in OpenBSD 3.0 and is now used in many other systems. They also replaced some tools with simpler licenses, like switching from CVS and pkg-config to other options that fit OpenBSD’s rules better.

Funding

The OpenBSD project mainly relies on support from everyday users who buy CDs or make donations. In the early 2000s, it also received help from DARPA and the POSSE project, which provided salaries, hardware, and funding for events.

In 2006, OpenBSD faced money problems, and companies like the Mozilla Foundation and GoDaddy helped it continue. Later, in 2014, a big donation in bitcoins and other contributions saved the project from closing.

OpenBSD Foundation

The OpenBSD Foundation is a Canadian non-profit organization created to help manage support for OpenBSD and related projects like OpenSSH, OpenBGPD, and LibreSSL. Since 2014, big companies such as Microsoft, Facebook, and Google have contributed to the foundation.

Distribution

OpenBSD can be obtained in different ways. You can get the source code using anonymous CVS, or download binary releases and development snapshots using FTP, HTTP, and rsync. Before version 6.1, you could order pre-packaged CD-ROM sets online for a small fee, which included stickers and a theme song. These helped support the project's costs for hardware and Internet services.

OpenBSD includes a package management system called pkg* tools to easily install and manage extra programs. These programs are stored as binary files and can be added, updated, or removed using the package tools. The system also has a ports collection, which contains makefiles and other tools needed to create these packages. The ports and the main operating system are developed and released together for each version.

Songs and artwork

OpenBSD used a special logo when it first started, created by an artist named Erick Green. Later, they chose a character named Puffy, a pufferfish, to represent the system. Puffy appears in songs and artwork for each release of OpenBSD. These songs and artworks often tell a fun story or share an important message about OpenBSD, sometimes by making funny copies of famous movies or songs.

Releases

The following table shows the version history of the OpenBSD operating system.