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1 - Introduction to OpenBSD
Table of Contents
1.1 - What is OpenBSD?
The OpenBSD project produces a freely
available, multi-platform 4.4BSD-based UNIX-like operating system.
Our goals place emphasis on correctness,
security, standardization, and
This FAQ specifically covers only the most recent release of OpenBSD.
1.2 - On what systems does OpenBSD run?
OpenBSD runs on the following platforms:
Available on CD means the official CD
set includes that platform and a small selection of useful
CD ISO images can be downloaded for most other platforms.
These are not the same as the official CD sets, however.
Some platforms also have USB disk images available.
More information on OpenBSD platforms can be found on the
People sometimes ask why we support so many "odd" machines.
The short answer is "because we want to."
If enough skilled people (and sometimes "enough" is only one really skilled
person!) wish to maintain support for a platform, it will be
There are practical benefits to keeping OpenBSD multi-platform: when new
platforms come out, the code tree is relatively free of portability-breaking
bugs and design flaws.
The OpenBSD platforms include 32 bit and 64 bit processors, little and
big endian machines, and many different designs.
And yes, supporting "unusual" platforms has helped produce a higher-quality
code base for more common platforms too.
1.3 - Why might I want to use OpenBSD?
New users frequently want to know whether OpenBSD is superior to some
other free UNIX-like operating system.
That question is largely unanswerable, and is the subject of countless
(and useless) religious debates.
Do not, under any circumstances, ask such a question on an OpenBSD mailing
Below are some reasons why we think OpenBSD is a useful operating system:
- OpenBSD runs on many different hardware
- OpenBSD is thought of by many security professionals as the
most secure UNIX-like operating system,
as a result of a never-ending comprehensive source code
- OpenBSD is a full-featured UNIX-like operating system available
in source form at no charge.
- OpenBSD integrates cutting-edge security technology suitable for
building firewalls and
private network services in a
- OpenBSD benefits from strong ongoing development in many areas,
offering opportunities to work with emerging technologies with an
international community of programmers and end users.
- OpenBSD attempts to minimize the need for customization and
For the vast majority of users, OpenBSD "Just Works" on their
hardware for their application.
Not only is tweaking and customizing rarely needed, it is actively
However, whether OpenBSD is right for you is a question that only you
1.4 - Is OpenBSD really free?
OpenBSD is all free.
The binaries are free.
The source is free.
All parts of OpenBSD have reasonable copyright terms permitting free
This includes the ability to REUSE most parts of the OpenBSD source tree,
either for personal or commercial purposes.
OpenBSD includes NO further restrictions other than those implied by the
original BSD license.
Software which is written under stricter licenses cannot be included in
the regular distribution of OpenBSD.
This is intended to safeguard the free use of OpenBSD.
For example, OpenBSD can be freely used for personal use, for academic use,
by government institutions, by non-profit making organizations and by
OpenBSD, or parts of it, can also be freely incorporated into
People sometimes ask if it bothers us that our free work is put into
The answer is that we would prefer that our good code be widely used
rather than have commercial software vendors reimplement and create badly
coded or incompatible alternative solutions to already solved problems.
For example, it is likely that SSH is a widely used protocol due to
this freedom, much more widely used than if restrictions had been placed
on how people used the OpenSSH code.
If a free SSH solution was not available for vendors to use (in their
multitude of rapidly developed products), they would have written or
purchased some crummy off-the shelf version instead.
This isn't to say we would object to
financial or hardware support in thanks.
In fact, it is stunning how little support of any kind comes from
companies that depend upon OpenBSD (or OpenSSH) for their products,
but there is no requirement of compensation.
For further reading on other popular licenses, read the
OpenBSD copyright policy.
The maintainers of OpenBSD support the project largely from their own
This includes the time spent programming for the project, equipment used
to support the many ports, the network resources used to distribute OpenBSD
to you, and the time spent answering questions and investigating users' bug
The OpenBSD developers are not independently wealthy, and even small
contributions of time, equipment and resources make a big difference.
1.5 - How can I help support OpenBSD?
We are greatly indebted to the people and organizations that have
contributed to the OpenBSD project.
Some are acknowledged by name on the
donations page. This is not done for everyone anymore, however.
OpenBSD has a constant need for several types of support from the user
If you find OpenBSD useful, you are strongly encouraged to find a way to
If none of the suggestions below are right for you, feel free to propose
an alternative by sending email to
- Buy an OpenBSD CD set.
It includes the current full release of OpenBSD and is bootable on
It also generates revenue to support the OpenBSD project, and reduces
the strain on network resources used to deliver the distribution via
This inexpensive three CD set includes the full source.
Your friends could also use a copy!
- Donate money.
The project has a constant need for cash to pay for equipment, network
connectivity, and expenses relating to CD publishing.
Manufacturing CDs requires an up-front out-of-pocket investment for the
OpenBSD developers, without guaranteed return.
Send an email to
firstname.lastname@example.org to find out how to contribute.
Even small donations make a profound difference.
- Donate equipment and parts.
The project has a constant need for general and specific hardware.
Items such as SCSI, SATA and SAS disks and various types of RAM are
For other types of hardware such as computer systems and motherboards,
you should inquire as to current need.
Write to email@example.com
to arrange the shipment.
- Donate your time and skills.
Programmers who enjoy writing operating systems are naturally always
welcome, but there are dozens of other ways that people can be useful.
Follow the mailing lists and help answer
questions from new users.
- Help maintain documentation by submitting new FAQ material
Form a local users group and get your
friends hooked on OpenBSD.
Make a case to your employer for using OpenBSD at work.
If you're a student, talk to your professors about using OpenBSD as
a learning tool for Computer Science or Engineering courses.
It's also worth mentioning one of the most important ways you should
not try to "help" the OpenBSD project: do not waste your time engaging
in operating system flame wars.
It does not help the project to find new users and can cause substantial
harm to important relationships that developers have with other developers.
1.6 - Who maintains OpenBSD?
OpenBSD is maintained by a development team spread across many different
The project is coordinated by Theo de Raadt, located in Canada.
1.7 - When is the next release of OpenBSD?
The OpenBSD team makes a new release every six months, with target release
dates in May and November.
More information on the development cycle can be found
1.8 - What is included with OpenBSD?
OpenBSD is distributed with a number of third-party software products,
As can be seen, the OpenBSD team often patches third party products,
typically to improve the security or quality of the code.
In some cases, the user will see no difference in operation.
In other cases, there ARE operational differences which may impact some users.
Keep these enhancements in mind before blindly adding different versions
of the same software.
You may get a bigger version number but a less secure system.
- X.org, the X Window environment,
with local patches.
Installed with the x*.tgz
install file sets.
- GCC, the GNU C Compiler.
Installed as part of the compXX.tgz file set.
- Perl, with patches and
improvements from the OpenBSD team.
- SQLite, with patches
and improvements from the OpenBSD team.
- NSD and
the authoritative name server and recursive caching resolver.
- gdb, with
- less, with
Much home-grown software is also included,
and additional applications can be added through the OpenBSD
packages and ports system.
1.9 - What is new in OpenBSD 5.8?
The complete list of changes made to OpenBSD 5.7 to create OpenBSD 5.8
can be found on plus58.html, and highlights
on the OpenBSD 5.8 information page, however
here are a few changes the OpenBSD team anticipate will require or
warrant some special note to people upgrading or installing OpenBSD 5.8
who are familiar with older versions:
- sudo removed in favor of
sudo is available as a package if needed.
More info on doas(1) can be found here.
- Root logins via SSH are actively discouraged.
Default is to prohibit root login via SSH.
- SSHv1 disabled at compile time.
You shouldn't be using this anyway.
Some other insecure protocols are disabled at runtime (i.e., config file
options can reactivate), but some old clients may notice.
This is a clue you should upgrade your client.
- OpenNTPD active by default on
new installs, and will by default use pool.ntp.org.
You can reconfigure it by editing
ntpd.conf(5) or disable it in /etc/rc.conf.local.
1.10 - Can I use OpenBSD as a desktop system?
This question is often asked in exactly this manner, with no explanation
of what "desktop" requirements entail.
The only person who can answer that question is you, as it depends on
what your needs and expectations are.
While OpenBSD has a great reputation as a "server" operating system, it
can be (and is) used on the desktop.
Many "desktop" applications are available through
packages and ports.
As with all operating system decisions, the question is: can it do the
job you desire in the way you wish?
You must answer this question for yourself.
It might be worth noting that a large amount of OpenBSD development is
done on laptops running OpenBSD.
1.11 - Why is/isn't ProductX included?
People often ask why a particular product is or isn't included with
The answer is based on two things: the wishes of the developers and
compatibility with the goals of the project.
A product will not be included simply because it is "nifty" -- it must
also be "free" for use, distribution and modification by our standards.
A product must also be stable and secure -- a bigger version number does
not always mean a better product.
Licensing is often the biggest problem: we want OpenBSD to remain usable
by any person anywhere in the world for any purpose.
Another major consideration is the wishes of the developers.
The OpenBSD developers are the ultimate judges of what does and doesn't
go into the project.
Just because an application is "good" doesn't mean the OpenBSD project
wishes to devote the resources needed to maintaining it, or that
they will share other's enthusiasm about its place in OpenBSD.
Some commonly asked questions about third party products:
In most cases, these topics have been discussed in painful detail on
the mailing lists.
Please see the archives if you need more information.
- Why is a web server included? It isn't needed by many people!
Because the developers want it.
- Why isn't bzip2 included instead of gzip?
Performance is horrible, and benefit is minimal.
Impact on slower platforms would be unacceptable.
- Why isn't there a graphical or
For a number of reasons, including the goal of keeping the installation
boot media able to be a single floppy disk, the fact that one installer
can be used on all platforms in all configurations, and the fact that
after the second or third OpenBSD install, most users find the OpenBSD
installation system among the fastest and easiest installers of any OS.
Most developers and users greatly prefer the speed, power, and ease of
use of the current installer to any of the more "colorful" or "pretty"
installers on some other platforms.
- Will ZFS be added to OpenBSD?
Not unless someone can convince Oracle to change the license for it to
something compatible with OpenBSD policy.
Of course, if you wish to use one of these packages and your use is
compatible with the license of the products, no one will stop you.
That wouldn't be very free if we tried, would it?
However, your needs may change -- you may not want to develop a
"Killer Application" that you can't sell, distribute, or get rich from
because you incorporated non-free software into it.
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