Comparison of BSD operating systems

There are a number of Unix-like operating systems based on or descended from the Berkeley Software Distribution (BSD) series of Unix variants. The three most notable descendants in current use are FreeBSD, OpenBSD, and NetBSD, which are all derived from 386BSD and 4.4BSD-Lite, by various routes. Both NetBSD and FreeBSD started life in 1993, initially derived from 386BSD, but in 1994 migrating to a 4.4BSD-Lite code base. OpenBSD was forked in 1995 from NetBSD. Other notable derivatives include DragonFly BSD, which was forked from FreeBSD 4.8, and Apple Inc.'s Mac OS X, with its Darwin base including a large amount of code derived from FreeBSD.

Most of the current BSD operating systems are open source and available for download, free of charge, under the BSD License, the most notable exception being Mac OS X. They also generally use a monolithic kernel architecture, apart from Mac OS X and DragonFly BSD which feature hybrid kernels. The various open source BSD projects generally develop the kernel and userland programs and libraries together, the source code being managed using a single central source repository.

In the past, BSD was also used as a basis for several proprietary versions of UNIX, such as Sun's SunOS, Sequent's Dynix, NeXT's NeXTSTEP, DEC's Ultrix and OSF/1 AXP (now Tru64 UNIX). Of these, only the last is still currently supported in its original form. Parts of NeXT's software became the foundation for Mac OS X, among the most commercially successful BSD variants in the general market.

Aims and philosophies

FreeBSD

The aim of FreeBSD is to produce an operating system usable for any purpose. It is intended to run a wide variety of applications, be easy to use, contain cutting edge features, and be highly scalable on very high load network servers. FreeBSD is free and open source, and the project prefers the BSD license. However, they sometimes accept non-disclosure agreements (NDAs) and include a limited number of closed-source HAL modules for specific device drivers in their source tree, to support the hardware of companies who do not provide purely open source drivers (such as HALs to program software-defined radios so that vendors do not share their proprietary algorithms). To maintain a high level of quality and provide good support for "production quality commercial off-the-shelf (COTS) workstation, server, and high-end embedded systems", FreeBSD focuses on a narrow set of architectures. A significant focus of development over the last five years has been fine-grained locking and SMP scalability. Other recent work includes Common Criteria security functionality, such as mandatory access control and security event audit support.

OpenBSD

OpenBSD aims at security, correctness, and being as free as possible. Security policies include revealing security flaws publicly, known as full disclosure; thoroughly auditing code for bugs and security issues; various security features, including the W^X page protection technology and heavy use of randomization; a "secure by default" philosophy including disabling all non-essential services and having sane initial settings; and integrated cryptography, originally made easier due to relaxed Canadian export laws relative to the United States. Concerning software freedom, OpenBSD prefers the BSD or ISC license, with the GPL acceptable only for existing software which is impractical to replace, such as the GNU Compiler Collection. NDAs are never considered acceptable. This has led to the founding of a number of child projects such as OpenSSH, OpenNTPD, OpenCVS, OpenBGPD, PF and CARP to replace restricted alternatives, and campaigns to persuade hardware vendors to release documentation. In common with its parent, NetBSD, OpenBSD strives to run on a wide variety of hardware.

NetBSD

NetBSD is designed to provide a freely redistributable operating system that professionals, hobbyists, and researchers can use in any manner they wish. The main focus is portability, through the use of clear distinctions between machine-dependent and machine-independent code. It runs on a wide variety of 32-bit and 64-bit processor architectures and hardware platforms, and is intended to interoperate well with other operating systems. NetBSD places emphasis on correct design, well-written code, stability, and efficiency. Where practical, close compliance with open API and protocol standards is also aimed for. In June, 2008, the NetBSD Foundation moved to a two clause BSD license, citing changes at UCB and industry applicability.

DragonFly BSD

DragonFly BSD is designed to be inherently easy to understand and develop for multi-processor capable infrastructures. Starting with FreeBSD 4.8, the main aim is to radically change the kernel architecture, introducing microkernel-like message passing which will enhance scalability and reliability on symmetric multiprocessing platforms, and also be applicable to NUMA and clustered systems. The long-term goal is to provide transparent single-system image clustering. DragonFly BSD currently supports both the IA-32 platform and the x86_64 (or AMD64) platform. Matthew Dillon, the founder of DragonFly BSD, believes supporting fewer platforms makes it easier for a project to do a proper ground-up SMP implementation.

Popularity

File:Bsd distributions usage.svg

Bar chart showing the proportion of users of each BSD variant from a BSD usage survey from September 2005.

In September 2005, the BSD Certification Group, after advertising on a number of mailing lists, surveyed 4,330 BSD users, 3,958 of whom took the survey in English, to assess the relative popularity of the various BSD operating systems. About 77% of respondents used FreeBSD, 33% used OpenBSD, 16% used NetBSD, 2.6% used Dragonfly, and 6.6% used other (potentially non-BSD) systems. Other languages offered were Brazilian and European Portuguese, German, Italian, and Polish. Note that there was no control group or pre-screening of the survey takers. Those who checked "Other" were asked to specify that operating system.

Because survey takers were permitted to select more than one answer, the percentages shown in the graph, which are out of the number survey of participants, add up to greater than 100%. If a survey taker filled in more than one choice for "other", this is still only counted as one vote for other on this chart.

Another attempt to profile worldwide BSD usage is the *BSDstats Project, whose primary goal is to demonstrate to hardware vendors the penetration of BSD and viability of hardware drivers for the operating system. The project collects data monthly from any BSD system administrators willing to participate, and currently records the BSD market share of FreeBSD, OpenBSD, NetBSD, DragonflyBSD, Debian GNU/kFreeBSD, PC-BSD, and MirBSD.

The DistroWatch website, well-known in the Linux community and often used as a rough guide to free operating system popularity, publishes page hits for each of the Linux distributions and other operating systems it covers. As of December 2009, using a data span of the last six months it placed FreeBSD in 12th place with 614 hits per day; PC-BSD in 24th place with 312 hits per day; OpenBSD in 53rd place with 154 hits per day; DragonFly in 62nd place with 135 hits per day; and NetBSD in 96th place with 87 hits per day.

Names, logos, and slogans

File:Freebsd-logo.png

FreeBSD's logo.

The names FreeBSD and OpenBSD are references to software freedom: both in cost and open source. NetBSD's name is a tribute to the Internet, which brought the original developers together.

The first BSD mascot was the BSD daemon, named after a common type of Unix software program, a daemon. FreeBSD still uses the image, a red cartoon daemon named Beastie, wielding a pitchfork, as its mascot today. In 2005, after a competition, a stylized version of Beastie's head designed and drawn by Anton Gural was chosen as the FreeBSD logo.

The NetBSD flag, designed in 2004 by Grant Bisset, is inspired by the original NetBSD logo, designed in 1994 by Shawn Mueller, portraying a number of BSD daemons raising a flag on top of a mound of computer equipment. This was based on a World War II photograph, Raising the Flag on Iwo Jima. The Board of Directors of The NetBSD Foundation believed this was too complicated, too hard to reproduce and had negative cultural ramifications and was thus not a suitable image for NetBSD in the corporate world. The new, simpler flag design replaced this. The NetBSD slogan is "Of course it runs NetBSD", referring to the operating system's portability.

File:Openbsd.png

OpenBSD's logo.

Originally, OpenBSD used the BSD daemon as a mascot, but later replaced it with Puffy. Although Puffy is usually referred to as a pufferfish, the spikes on the cartoon images give him a closer likeness to the porcupinefish. The logo is a reference to the fish's defensive capabilities and to the Blowfish cryptography algorithm used in OpenBSD. OpenBSD also has a number of slogans including "Secure by default", which was used in the first OpenBSD song, 'E-railed', and "Free, Functional & Secure" and has released an original song with every release since 3.0.

The DragonFly BSD logo, designed by Joe Angrisano, is a dragonfly named Fred. A number of unofficial logos by various authors also show the dragonfly or stylized versions of it. DragonFly BSD considers itself to be "the logical continuation of the FreeBSD 4.x series." FireflyBSD has a similar logo, a firefly, showing its close relationship to DragonFly BSD. In fact, the FireflyBSD website states that proceeds from sales will go to the development of DragonFly BSD, suggesting that the two may in fact be very closely related.

PicoBSD's slogan is "For the little BSD in all of us," and its logo includes a version of FreeBSD's Beastie as a child, showing its close connection to FreeBSD, and the minimal amount of code needed to run as a Live CD.

A number of BSD OSes use stylized version of their respective names for logos. This includes Mac OS X (which only uses the X), PC-BSD, DesktopBSD (with a symbol on the side), ClosedBSD (curved into a semicircle), Frenzy (with symbol on the side), and MicroBSD (which includes a bull-like M with yellow eyes). The Mac OS X logo is the Roman numeral for 10. This is intended to emphasize the change from previous versions of Mac OS, which were not based on BSD and had version numbers expressed using Arabic numerals. PC-BSD's slogan is "Personal computing, served up BSD style!", DesktopBSD's "A Step Towards BSD on the Desktop." MicroBSD's slogan is "The small secure unix like OS."

MirOS's site collects a variety of BSD mascots and Tux, the Linux mascot, together, illustrating the project's aim of supporting both BSD and Linux kernels. MirOS's slogan is "a wonderful operating system for a world of peace."

General information

	Primary developers	First public release	Based on	Latest stable version		Cost (USD)	Preferred license	Purpose	Short description
				Version	Release Date
FreeBSD	The FreeBSD Project	Dec 1993	386BSD, 4.4BSD-Lite	8.0	25 November 2009	Free	BSD	Server, Workstation, Network Appliance, Embedded	Aims for maximum performance.
OpenBSD	The OpenBSD Project	July 1996	NetBSD	4.6	18 Oct 2009	Free	ISC	Server, Workstation, Network Appliance, Embedded	Aims for maximum security.
NetBSD	The NetBSD Project	May 1993	386BSD, 4.4BSD-Lite	5.0.1	2 Aug 2009	Free	BSD	Server, Workstation, Network Appliance, Embedded	Aims for maximum portability.
DragonFly BSD	Matt Dillon	12 Jul 2004	FreeBSD 4.8	2.4.1	O1 Oct 2009	Free	BSD	Server, Workstation, Network Appliance, Embedded	Emphasis on multiprocessor systems, and clustering
386BSD Template:Fn	William and Lynne Jolitz	Mar 1992	4.3BSD Net/2	1.0	1994	Free	BSD		Historical
BSD/OS (BSD/386) Template:Fn	BSDi, Wind River Systems	Mar 1993	4.3BSD Net/2, 4.4BSD	5.1	Oct 2003		Proprietary		Historical
SunOS Template:Fn	Sun Microsystems	1982	4.xBSD, UNIX System V	4.1.4	Nov 1994Template:Fn		Proprietary		Historical (Solaris is a different code base)
Ultrix Template:Fn	Digital Equipment Corporation	1984	4.2BSD, SVR2	4.5	1995		Proprietary		Historical
Tru64 UNIX (OSF/1 AXP, Digital UNIX)	DEC, Compaq, HP	1993	4.3BSD, 4.4BSD, Mach 2.5, UNIX System V	5.1B-4	Dec 2006	Non-free$99 (non- commer- cial)	Proprietary
Mac OS X	Apple Inc.	Mar 2001	Darwin	10.6 "Snow Leopard"	28 August 2009	Non-freeDesktop $29 when upgrading from 10.5 $169 (including iLife 09 and iWork 09) when upgrading from earlier versions Server $499 (unlimited clients)	Open source core system (APSL, GPL, others) with proprietary higher level API layers	Workstation, Home Desktop, Server	Ships with Apple hardware and is locked to it.
Darwin	Apple Inc.	Mar 2001	NeXTSTEP, FreeBSD, Mac OS	9.2	11 February 2008	Free	APSL, GPL, others	Workstation, Home Desktop, Server	The kernel and certain userland components of OS X
PC-BSD	Kris Moore, Mike Albert, Tim McCormick, Dimitri Tishchenko	29 Apr 2006	FreeBSD	7.1.1 "Galileo"	06 Jul 2009	Free	BSD	Desktop	Easy to use while maintaining full use of FreeBSD base
DesktopBSD	Peter Hofer, Daniel Seuffert	25 Jul 2005	FreeBSD	1.7	07 Sept 2009	Free	BSD	Desktop	Easy to use
ClosedBSD	Joshua Bergeron and various contributors		FreeBSD	1.0B (floppy), 1.0-RC1 (CD)		Free	Proprietary		firewall/NAT, boot floppy, Live CD
FreeSBIE			FreeBSD	2.0.1	Feb 2007	Free		Live CD of FreeBSD
Frenzy	Mozhaisky Sergei		FreeBSD	1.1	08 Dec 2008	Free		"portable system administrator toolkit"	Live CD
PicoBSD	Michael Bialecki		FreeBSD	0.42		Free	BSD	boot floppy
polyBSD	FOSS Tools Team		NetBSD	3.1		Free	BSD	live USB	development platform for embedded systems
Anonym.OS		beta as of Jan 2005	OpenBSD 3.8	none		Free		Anonymous browsing	Live CD
MirOS BSD	The MirOS Project		OpenBSD 3.1	#10	16 Mar 2008	Free		European
ekkoBSD Template:Fn	Rick Collette		OpenBSD 3.3					Server	easy to administer
MicroBSD Template:Fn	Bulgarians		OpenBSD 3.0/3.4	0.6	27 Oct 2003	Free		General purpose	Small, secure
OliveBSD	Gabriel Paderni		OpenBSD 3.8			Free		Live CD
Gentoo/FreeBSD	Gentoo Linux developers		FreeBSD			Free	GPL, BSD	Server, Workstation, Network Appliance	uses Gentoo framework
Gentoo OpenBSD	Gentoo Linux developers		OpenBSD			Free	GPL, BSD	Server, Workstation, Network Appliance, Embedded	uses Gentoo framework
Gentoo NetBSD	Gentoo Linux developers		NetBSD			Free	GPL, BSD	Server, Workstation, Network Appliance, Embedded	uses Gentoo framework
Gentoo DragonflyBSD	Robert Sebastian Gerus (project not yet officially supported by Gentoo)		DragonFly BSD			Free		Server, Workstation, Network Appliance	uses Gentoo framework
Debian GNU/kFreeBSD			GNU, FreeBSD			Free			GNU userspace on FreeBSD kernel
Debian GNU/NetBSD			GNU, NetBSD			Free			GNU userspace on NetBSD kernel
MidnightBSD	Lucas Holt		FreeBSD 6.0	none	none	Free	BSD	Desktop	GNUstep based Desktop Environment
pfSense	various contributors	1.0	FreeBSD	1.2	25 Feb 2008	Free	BSD	Security appliance	firewall/NAT, Live CD
Paxym-FreeBSD for Octeon/Mips	Paxym Inc. OS/Kernels team	4.0 - 11-Dec-2007	FreeBSD 7.0	4.7	13 Aug 2008		Proprietary	Network, Storage, Security Applications: Routers/UTM/Firewall/NAS	For Mips32, Mips64, SMP Mips64 Octeon Cavium Networks 1-16 Multicore CPU [1]
	Developer	First public release	Based on	Version	Release Date	Cost (USD)	Preferred license	Purpose	Short description

Template:Fnb 386BSD, BSD/OS, SunOS, and Ultrix are historic operating systems that are no longer developed. BSDeviant and ekkoBSD do not exist anymore either, although BSDeviant is still available for download (see external links). MicroBSD ended, then started again in 2003, but it does not seem that any progress has been made since then, though the website still exists.
Template:FnbThis article only refers to SunOS through version 4.x. SunOS from release 5.x forward is based on SVR4, and is most commonly referred to as the Solaris Operating System.

Technical information

	Supported architectures	Supported file systemsTemplate:Fn	Kernel type	GUI on by defaultTemplate:Fn	Package management	Update management	Primary APIsTemplate:Fn
FreeBSD	x86, x86-64, PC98, Itanium, UltraSPARC, ARM, MIPS, PPC, others	UFS, UFS2, ext2, FAT, ISO 9660, UDF, NFS, SMBFS, NetWare (nwfs), NTFS (limited read-write), ReiserFS (read only), XFS (experimental), ZFS, FUSE, Coda (experimental), AFS, others	Monolithic with modules	No (X.Org available)	ports tree, packages	source (CVSup, portsnap), network binary update (freebsdupdate)	BSD, POSIX
OpenBSD	x86, 68k, Alpha, x86-64, SPARC, VAX, others	UFS, UFS2, ext2, FAT, ISO 9660, UDF, NFS, NTFSTemplate:Fn (read only), AFS, others	MonolithicTemplate:Fn	No (X.Org included)Template:Fn	ports tree, packages	source (CVS, CVSup, rsync) or binary upgrade	BSD, POSIX
NetBSD	x86, 68k, Alpha, x86-64, PPC, SPARC, UltraSPARC, PowerPC, ARM, others	UFS, UFS2, ext2, FAT, ISO 9660, NFS, LFS, UDF, SMBFS, Coda, HFS+ (read only), EFS (read only), NTFS (read only), TMPFS, FUSE, PUFFS (BSD replacement of FUSE), ADOS (AmigaDOS file system), filecorefs (Acorn RISC OS file system), others	Monolithic with modules	No (X.Org or XFree86 included)Template:Fn	pkgsrc, packages	source (CVS, CVSup, rsync) or binary (using sysinst)	BSD, POSIX
Ultrix	VAX, PDP-11, MIPS	UFS + others	Monolithic	No (X11 included)	setld	unknown	BSD, POSIX (4.0 onwards)
Tru64 UNIX	Alpha	UFS, AdvFS, ISO 9660, UDF, NFS	Hybrid	Yes (CDE)	setld	dupatch	POSIX, UNIX 98, X11, CDE, others
Mac OS X / Darwin	PPC, x86, x86-64, ARM	HFS+ (default), HFS, UFS, AFP, ISO 9660, FAT, UDF, NFS, SMBFS, NTFS (read only), FTP, WebDAV, others	Hybrid	Yes (Aqua)	OS X Installer	Software Update	Carbon, Cocoa, BSD/POSIX, CF, X11 (since 10.3)
DragonFly BSD	x86, x86-64	HAMMER, UFS, FAT, ISO 9660, NFS, SMBFS, NTFS (read only), ext2, others	Hybrid	No (X.Org available)	pkgsrc, packages	Git	BSD, POSIX
PC-BSD	x86, x86-64	UFS, UFS2, FAT, ISO 9660, NFS, SMBFS, NTFS (read only), others	Monolithic with modules	Yes (KDE)	graphical installation wizard, ports tree	CVSup, Portsnap, network binary update (Online Update)	BSD, POSIX, X11, KDE
MidnightBSD	x86, x86-64	UFS, UFS2, ext2, FAT, ISO 9660, UDF, NFS, SMBFS, NetWare (nwfs), NTFS (read only), others	Monolithic with modules	No (X.Org available)	ports tree, packages	source CVSup	BSD, POSIX, X11, GNUstep

Template:Fnb UFS and UFS2 are descendants of the old FFS. However, many BSD operating systems refer to UFS1 as FFS.
Template:Fnb Operating systems where the GUI is not installed and turned on by default are often bundled with an implementation of the X Window System. However, installing X is usually optional.
Template:Fnb Most operating systems use proprietary APIs in addition to any supported standards.
Template:Fnb OpenBSD's NTFS support is not enabled by default and requires a custom kernel.
Template:Fnb OpenBSD contains support for modules on some architectures. They are used only to add third-party features: extracting existing functions into modules in the same manner as FreeBSD is not possible.
Template:Fnb Unlike FreeBSD, OpenBSD includes the X Window System as base install sets rather than packages within the ports collection. It includes some local changes and is managed as part of the OpenBSD source tree.
Template:Fnb NetBSD includes either X.Org or XFree86 (depending on platform) as a base install set and includes some local changes, maintained within the NetBSD source tree.

Security features

	Resource access control	Security logging	Subsystem isolation mechanisms	Integrated firewall	Encrypted file systems	Data execution prevention
						hardware	emulation
FreeBSD	Unix, ACLs, MAC	syslog, CAPP event auditing, OpenBSM	chroot, jail, MAC partitions	IPFW2, IPFilter, PF	Yes	Yes	No
OpenBSD	Unix	syslog	chroot, systrace, privilege separation	PF	YesTemplate:Fn	Yes	Yes
NetBSD	Unix, Veriexec	syslog	chroot, privilege separation	IPFilter, PF	Yes	Yes	No
Mac OS X	Unix, ACLs	syslog, CAPP event auditing, OpenBSM	chroot, sandbox	IPFW2	Yes	Yes	unknown
PC-BSD	Unix, ACLs, MAC		chroot, jail, MAC Partitions	IPFW2, IPFilter, PF	YesTemplate:Fn	Yes	No
DragonFly BSD	Unix	syslog	chroot, jail, VKernel	IPFW2, IPFilter, PF	Yes	No	No
MidnightBSD	Unix, ACLs, MAC	syslog	chroot, jail, MAC partitions	IPFW2, IPFilter, PF	Yes	No	No

Template:Fnb Swap space encrypted by default on OpenBSD 3.8 and above

Template:Fnb Additionally swap space may be encrypted during installation, uses memory based tmp file storage by default.

See also

• List of BSD operating systems
• BSD license
• Comparison of open source operating systems
• Comparison of operating systems

Notes and references

Other sources

• Milo et al. (1998-06-22 - 2004-03-31). "FreeBSD". Operating System Technical Comparison. OSdata. http://www.osdata.com/oses/freebsd.htm. Retrieved 2006-06-02. 
• Milo et al. (1998-06-22 - 2004-04-19). "OpenBSD". Operating System Technical Comparison. OSdata. http://www.osdata.com/oses/openbsd.htm. Retrieved 2006-06-02. 
• Milo et al. (1998-06-22 - 2004-04-19). "NetBSD". Operating System Technical Comparison. OSdata. http://www.osdata.com/oses/netbsd.htm. Retrieved 2006-06-02. 
• Milo et al. (1998-06-22 - 2002-02-17). "SunOS". Operating System Technical Comparison. OSdata. http://www.osdata.com/oses/sunos.htm. Retrieved 2006-06-02. 
• "SunOS & Solaris version history". Berkeley. http://www.ocf.berkeley.edu/solaris/versions/. Retrieved 2006-06-02. 
• "Ultrix FAQ". 1996-11-04. http://www.supelec.fr/decus/faq/faq-ultrix.html. Retrieved 2006-06-02. 
• Milo et al. (1998-06-22 - 2002-04-10). "Ultrix". Operating System Technical Comparison. OSdata. http://www.osdata.com/oses/ultrix.htm. Retrieved 2006-06-02. 
• Milo et al. (1998-06-22 - 2002-03-20). "Mac OS X". Operating System Technical Comparison. OSdata. http://www.osdata.com/oses/macosx.htm. Retrieved 2006-06-02. 
• Milo et al. (1998-06-22 - 2002-03-20). "Mac OS X Server". Operating System Technical Comparison. OSdata. http://www.osdata.com/oses/mxs.htm. Retrieved 2006-06-02. 
• "BSDeviant download page". Bsdeviant.org. http://bsdeviant.org/. Retrieved 2008-06-30.  A semi-official download page.
• "ekkoBSD 1.0 BETA1B Released". Slashdot. 2003-11-25. http://bsd.slashdot.org/article.pl?sid=03/11/25/2331244. Retrieved 2006-06-03. 
• Milo et al. (1998-05-31 - 2006-02-01). "Operating System Technical Comparison". OSdata. http://www.osdata.com/. Retrieved 2006-06-02. 
• Brown, Martin (2004-08-10). "Differentiating Among BSD Distros". Jupitermedia Corporation. pp. 4. http://www.serverwatch.com/tutorials/article.php/3393051. Retrieved 2006-06-03. 
• Schneider, Wolfram; Gilliam, Josh and Schultz, Steven M. (1997-2004). "The UNIX system family tree: Research and BSD" (ASCII). The NetBSD Foundation. ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-current/src/share/misc/bsd-family-tree. Retrieved 2006-06-03.