Dictionary Thesaurus Word Dynamo Quotes Reference Translator Spanish

Comparison of operating systems

Desktop OS market share as of September, 2008
Windows - 92.24%
Mac OS X - 5.33%
Linux - 1.12%
Other - 1.32%

These tables compare general and technical information for a number of widely used and currently available operating systems.

Due to the large number and variety of available Linux distributions, they are all grouped under a single entry; see comparison of Linux distributions for a detailed comparison. There are also a variety of BSD operating systems, covered in comparison of BSD operating systems. For information on views of each operating system, see operating system advocacy.

General information

Name	Creator	First public release	Predecessor	Latest stable version	Latest release date	Cost/Availability	Preferred license	Target system type
AIX	IBM	1986-?-?	System V R3	6.1	2007-11-?	Bundled with hardware	Proprietary	Server, NetApp, Workstation
AmigaOS	Amiga, Inc.	1985-07-23	TRIPOS (as the disk operating component of AmigaOS)	4.1	2008-09-16	Bundled with hardware	Proprietary, Clones available under GNU GPL	Workstation, Home Desktop
FreeBSD	The FreeBSD Project	1993-12-?	386BSD	7.0	2008-02-27	Free	BSD	Server, Workstation, NetApp, Embedded
Haiku	Haiku Inc.	-	BeOS R5		(Nightly builds)	Free	MIT License	Home Desktop
HP-UX	Hewlett-Packard	1983-?-?	Unix	11.31 "11i v3"	2007-02-15	$400	Proprietary	Server, Workstation
IBM i	IBM	1988-?-?	OS/400	V6R1	2008-04-?	Bundled with hardware	Proprietary	Server
IRIX	SGI	1988-?-?	Unix	6.5.30	2006-08-16	Bundled with hardware	Proprietary	Server, Workstation
Inferno	Bell Labs	1997-?-?	Plan 9	Fourth Edition	2007-02-?	Free	MIT/GNU GPL/GNU LGPL/LPL	NetApp, Server, Embedded
Linux	Linus Torvalds, et al.	1992-?-?	Unix, Minix	Linux kernel 2.6.26.1; GNU C Library 2.7	2008-08-01; 2007-10-23	See Comparison of Linux distributions	GNU GPL, GNU LGPL and other licenses	See: Comparison of Linux distributions
Mac OS	Apple Inc.	1984-01-24	None	9.2.2	2002-05-12	Bundled with 68K and PowerPC Macs; versions 7-9 sold as retail upgrades	Proprietary	Workstation, Home Desktop
Mac OS X	Apple Inc.	2001-03-24	NeXTSTEP / OPENSTEP / Rhapsody, Mac OS	10.5.5 "Leopard"	2008-09-15	Bundled with hardware; also sold separately: Desktop $129 (Single User) Family Pack $199 (5 license)	Open source core system (Both Intel and PowerPC versions) (APSL, GNU GPL, others) with proprietary higher level API layers	Workstation, Home Desktop, Mobile (embedded)
Mac OS X Server	Apple Inc.	2001-03-24	NeXTSTEP / OPENSTEP / Rhapsody, Mac OS	10.5.5 "Leopard Server"	2008-09-15	Bundled with hardware; also sold separately: $499 (10 clients) $999 (unlimited clients)	Open source core system (Both Intel and PowerPC versions) (APSL, GNU GPL, others) with proprietary higher level API layers	Server
Minix3	Andrew S. Tanenbaum	2005-10-?	Minix2	3.1.2a	2006-05-29	Free	BSD	Workstation
NetBSD	The NetBSD Project	1993-05-?	386BSD	4.0	2007-12-19	Free	BSD	NetApp, Server, Workstation, Embedded
NetWare	Novell	1985	S-Net	6.5 SP7	2007-10-?	$184 (single-user)	Proprietary	Server
OpenBSD	The OpenBSD Project	1995-10-?	NetBSD 1.0	4.3	2008-05-01	Free	BSD	Server, NetApp, Workstation, Embedded
OpenVMS	DEC (now HP)	1978-02-?	RSX-11M	8.3	2006-08-?	Free for non-commercial use	Proprietary	Server, Workstation
OS/2	IBM and Microsoft	1987-12-?	MS-DOS, Windows 3.x	4.52	2001-12-?	$300	Proprietary	Home Desktop, Server
PC-BSD	PC-BSD Software	2006-?-?	FreeBSD	1.51	2008-04-23	Free	BSD	Desktop, Workstation, Server
Plan 9	Bell Labs	1993-?-?	Unix	Fourth Edition	(Daily snapshots)	Free	LPL	Workstation, Server, Embedded, HPC
QNX	QNX Software Systems	1982-?-?	Unix	6.3.2	2006-09-28	?	Proprietary	Workstation, Server, Embedded
Solaris	Sun	1992-07-?	SunOS	10 5/08	2008-04-15	Free	CDDL	Server, Workstation
Windows Server (NT family)	Microsoft	1993-07-27	MS-DOS, OS/2, Windows 3.x	Windows Server 2008 (NT 6.0)	2008-02-27	$469 Web Server; other editions dependent on number of CALs purchased	Proprietary	Server, NetApp, Embedded, HPC
Microsoft Windows (NT family)	Microsoft	1985-11-20	MS-DOS, OS/2, Windows 3.x	Windows Vista (NT 6.0)	2006 November - 2007 January	Home Basic (Retail) $99.95, Home Premium (Retail) $129.95, Business (Retail) $199.95, Ultimate (Retail) $219.95	Proprietary	Workstation, Home Desktop, media center, Tablet PC, embedded
RISC OS	Acorn Computers, RISC OS Limited, Castle Technology Ltd	1989-04-?	ARTHUR, also the BBC Master OS	RISC OS 6.10 Select4i4 and RISC OS 5.13"	2008-05-28	$127 (£70)	Proprietary; originally bundled with computer	educational desktop, home computer
ZETA	yellowTAB	2005-06-?	BeOS R5	1.2	2006-04-27	Professional $110, Student $80	Proprietary	Home Desktop, Media Workstation
STOP 6 / XTS-400	BAE Systems	2003-?-?	STOP 5 / XTS-300	6.4.U1	2007-06-?	Unknown; supplied to customers on-demand by BAE Systems	Proprietary	Server, Workstation, cross-domain solution, network guard
ReactOS	ReactOS development team	1996-?-?	Windows NT	0.3.4	2008-01-22	Free	GNU GPL, GNU LGPL	Workstation, Home Desktop
z/OS	IBM	2000	OS/390	1.9	2007	Monthly License Charge (about $130 and up)	Proprietary	IBM mainframe
Name	Creator	First public release	Predecessor	Latest stable version	Latest release date	Cost/Availability	Preferred license	Target system type

Most OS distributions include bundled software with various other licenses.
Although Lisa OS ran on the same (albeit a slower version) microprocessor and was developed by Apple Computer at the same time as Mac OS, they were developed as different projects, sharing only a similar GUI between them.

Mac OS versions up to 7.5.5 are available free of charge here
GNU is a recursive acronym for GNU's Not Unix, which was chosen because its design is Unix-like, but differs from Unix by being Free software and by not containing any Unix code.
Minix inspired the Linux kernel. No code from Minix was used to create the Linux kernel.
PC-BSD uses FreeBSD as a base system with custom configuration and several desktop oriented tools to create an easy to use FreeBSD system for Desktops and Workstations.
Mac OS 7.6 was the first Mac OS operating system to be labeled Mac OS. Operating systems prior to this were named System Software 0.1 (available only to developers) through System Software 7.5, and known as System #.# for short.
Windows Vista was released to manufacturing on November 8 2006, and was subsequently made available to software developers and businesses in November 2006, with retail availability following on January 30 2007

Technical information

Name	Computer architectures supported	File systems supported	Kernel type	Source lines of code	GUI default is on	Package management	Update management	Native APIs	Non-native APIs supported through subsystems
AIX	PowerPC	JFS, JFS2, ISO 9660, UDF, NFS, SMBFS, GPFS	Monolithic		No	installp, RPM	Service Update Management Assistant (SUMA)	SysV, POSIX
AmigaOS	68k, PPC (x86 Clone available, see: AROS)	Proprietary (OFS, FFS,SFS, PFS), FAT, ISO 9660, UDF, many others via 3rd party drivers, such as SMBFS, etc.	Microkernel		Yes	Installer (almost not necessary)	AmiUpdate (almost not necessary)	Proprietary	UNIX (BSD) (available through 3rd party ixemul.library)
FreeBSD	x86, x86-64, PC98, SPARC, others	UFS2, ext2, ext3, FAT, ISO 9660, UDF, NFS, ReiserFS (read only), XFS (experimental), ZFS (experimental) and others	Monolithic with modules		No	ports tree, packages	by source (CVSup, portsnap), network binary update (freebsdupdate)	POSIX, BSD	Win16, Win32, Linux
Haiku	x86, 68k	BFS (default), FAT, ISO 9660	Microkernel		Yes	-	None	POSIX, BeOS API
HP-UX	PA-RISC, IA-64	VxFS, HFS, ISO 9660, UDF, NFS, SMBFS	Monolithic with modules		No	swinstall	swa (HP-UX Software Assistant)	SysV, POSIX
Linux	x86, x86-64, PPC, SPARC, Alpha, others	ext2, ext3, ext4, ReiserFS, FAT, ISO 9660, UDF, NFS, and others	Monolithic with modules	~ 9 million	See: Comparison of Linux distributions			POSIX, LSB, QT or GTK	Mono, Java, Win16, Win32
Inferno	x86, PPC, SPARC, Alpha, MIPS, others	Styx/9P2000, kfs, FAT, ISO 9660	Monolithic with modules, user space file systems		Yes			Proprietary
Mac OS Classic	68k, PPC	HFS+, HFS, AFP, ISO 9660, FAT, UDF	Monolithic with modules		Yes	None	Software Update	Toolbox, Carbon (from version 8.1)
Mac OS X	PPC, x86, x86-64, ARM	HFS+ (default), HFS, UFS, AFP, ISO 9660, FAT, UDF, NFS, SMBFS, NTFS, FTP, WebDAV, ZFS (experimental)	Hybrid	~86 million	Yes	Mac OS X Installer	Software Update	Carbon, Cocoa, Java, BSD/POSIX, X11 (since 10.3)	Toolbox (only in versions up to Mac OS X 10.4, not supported on x86 architecture), Win16, Win32
Minix3	x86		Microkernel	4000	No			POSIX
NetBSD	x86, x86-64, PPC, SPARC, 68k, Alpha, others	UFS, UFS2, ext2, FAT, ISO 9660, NFS, LFS, and others	Monolithic with modules		No	pkgsrc	by source (CVS, CVSup, rsync) or binary (using sysinst)	BSD, POSIX
NetWare	x86	NSS, NWFS, FAT, NFS, AFP, UDF, CIFS, ISO 9660	Hybrid		Yes	NWCONFIG.NLM, RPM, X11-based GUI installer	binary updates, ZENWorks for Servers, Red Carpet	Proprietary
OES-Linux	x86 PPC	NSS, NFS, AFP, UDF, CIFS, ISO 9660, Netware Traditional File System	Monolithic with modules		No	RPM, X11-based GUI installer	binary updates, ZENWorks for Server, Red Carpet	Proprietary(?)
OpenBSD	x86, x86-64, SPARC, 68k, Alpha, VAX, others	ffs, ext2, FAT, ISO 9660, NFS, some others	Monolithic with modules		No	ports tree, packages	by source	BSD, POSIX
OpenVMS	VAX, Alpha, IA-64	Files-11 (ODS), ISO 9660, NFS, CIFS	Monolithic with modules		No	PCSI, VMSINSTAL		Proprietary	POSIX
OS/2	x86	HPFS, JFS, FAT, ISO 9660, UDF, NFS	Monolithic		No	Feature Install and others		Proprietary, DOS API, Win16	Win32
PC-BSD	x86	UFS2, ext2, ext3, FAT, ISO 9660, UDF, NFS, ReiserFS (read only), XFS (experimental) and others	Monolithic with modules		Yes	ports tree, packages, PBI Graphical Installers	by PBI updates, source (CVSup, portsnap), network binary update (freebsdupdate)	BSD, POSIX, QT	Win16, Win32
Plan 9	x86, Alpha, MIPS, PPC, SPARC, others	fossil/venti, 9P2000, kfs, ext2, FAT, ISO 9660	Monolithic, user space file systems		Yes	None	replica	Proprietary (Unix-like)	POSIX compatibility layer
ReactOS	x86, PowerPC	FAT	Hybrid	1-2 mil	Yes	None	None	Win16, Win32, NT API
RISC OS	ARM (both 26 and 32-bit)	Acorn ADFS, Econet ANFS, FAT, ISO 9660, many others as loadable filesystems	Unprotected monotasking microkernel with large number of relocatable modules		Yes	Applications self-contained; hardware drivers often in ROM	!IyoUpWtch	Huge number of SWI calls; extensive C libraries
Solaris	x86, x86-64, SPARC	UFS, ZFS, ext2, FAT, ISO 9660, UDF, NFS, QFS, some others	Monolithic with modules		Yes	SysV packages (pkgadd)	Sun Connection	SysV, POSIX, GTK	Win16, Win32
STOP 6 / XTS-400	x86	Proprietary	Monolithic		No	RPM for some untrusted applications	Binary updates via postal mail and proprietary tools	some SysV, some POSIX, some Linux, some proprietary
Windows Server (NT family)	x86, x86-64, IA-64	NTFS, FAT, ISO 9660, UDF; 3rd-party drivers support ext2, ext3, reiserfs, and HFS	Hybrid	~45 million	Yes	MSI, custom installers	Windows Update	Win32, NT API	DOS API, Win16 (only in 32-bit versions), POSIX, .NET
Windows (NT family)	x86, x86-64	NTFS, FAT ISO 9660, UDF; 3rd-party drivers support ext2, ext3, reiserfs, and HFS	Hybrid	~ 40(XP)/64(Vista) million	Yes	MSI, custom installers	Windows Update	Win32, NT API	DOS API, Win16 (only in 32-bit versions), POSIX, .NET
ZETA	x86	BFS (default), FAT, ISO 9660, UDF, HFS, AFP, ext2, CIFS, NTFS (read only), ReiserFS (read only, up to v3.6)	Hybrid		Yes	SoftwareValet, script-based installers	None	POSIX, BeOS API
z/OS	z/Architecture	VSAM catalogs, HFS, zFS, etc.	Monolithic		No	SMP/E	SMP/E	Access methods, etc.	POSIX
Name	Computer architectures supported	File systems supported	Kernel type	Source lines of code	GUI default is on	Package management	Update management	Native APIs	Non-native APIs supported through subsystems

Operating systems where the GUI is not installed and turned on by default are often bundled with an implementation of the X Window System, installation of which is usually optional.
Most operating systems use proprietary APIs in addition to any supported standards.
NetBSD and OpenBSD include the X Window System as base install sets, managed in their respective main source repository, including local modifications. Packages are also provided for more up-to-date versions which may be less tested.
Windows can read and write with Ext2 and Ext3 file systems only when a driver from FS-driver or ext2fsd is installed. However, using Explore2fs, Windows can read from, but not write to, Ext2 and Ext3 file systems. Windows can also access ReiserFS through rfstool and related programs.
only i686 CPU
Amiga OS features since OS 2.0 version a standard centralized Install utility called Installer, which could be used by any software house to install programs. It works as a LISP language interpreter, and install procedures could be listed as simple text. AmigaOS can also benefit of a 3rd party copyrighted library called XAD that is available for all POSIX (Unix, Linux, BSD, and for AmigaOS, MorphOS, etc.). This library is freely distributable and publicly available on Aminet Amiga centralized repository of all Open Source or Free programs and utilities. XAD.Library, complete with GUI Voodoo-X, is based on modules and capable to manage over 300 compression methods and package systems (Voodoo-X GUI supports 80 package systems), including those widely accepted as standards such as .ZIP, .CAB, .LHA, .LZX, .RPM, etc.
A standard AmigaOS installation requires usually only few files (typically 3 to 10 files) to be copied in their appropriate directory, and libraries and language files for national localization to be put in their standard OS directories. Any Amiga user with some minimal experience knows where these files should be copied and could perform programs installations by hand.
AmiUpdate is capable to update AmigaOS files and also all Amiga programs which are registered to use the same update program that is standard for Amiga. Updating AmigaOS requires only few libraries to be put in standard OS location (for example all libraries are stored in "Libs:" standard virtual device and absolute path finder for "Libs" directory, Fonts are all in "Fonts:" absolute locator, the files for language localization are all stored in "Locale:", and so on). This leaves Amiga users with a minimal knowledge of the system almost free to perform by hand the update of the system files.

Security

	Resource access control	Subsystem isolation mechanisms	Integrated firewall	Encrypted file systems	No execute (NX) page flag		Known unpatched vulnerabilities
	Resource access control	Subsystem isolation mechanisms	Integrated firewall	Encrypted file systems	Hardware	Emulation	Number	Oldest
AIX	Unix, ACLs	chroot	IP Filter, IPSec VPNs, basic IDS			n/a	3	2002-10-11
FreeBSD	Unix, ACLs, MAC	chroot, jail, MAC Partitions	IPFW2, IPFilter, PF				3	2006-10-11
HP-UX	Unix, ACLs	chroot	IPFilter				4	2002-12-12
Inferno	Unix	Namespaces					colspan="2"
Linux	Unix, ACLs, MAC	chroot, Capability-based security, seccomp, SELinux	Netfilter/Varied by distribution				13	2004-05-10
Mac OS Classic							0	-
Mac OS X	Unix, ACLs	chroot	ipfw			(Intel Only)	5	2006-11-22
NetBSD	Unix, Veriexec, PaX, kauth	chroot, systrace, kauth	IPFilter, PF				colspan="2"
NetWare	Directory-enabled ACLs	Protected Address Spaces	IPFLT.NLM				colspan="2"
OES-Linux	Directory-enabled ACLs	chroot	IPFilter				colspan="2"
OpenBSD	Unix	chroot, systrace	PF				1	2007-08-16
OpenVMS	ACLs, Privileges	logical name tables					0	-
OS/2 / eComStation	ACLs						colspan="2"
PC-BSD	Unix, ACLs, MAC	chroot, jail, MAC Partitions	IPFW2, IPFilter, PF				1	2006-09-26
Plan 9	Unix (?)	Namespaces	ipmux				colspan="2"
Solaris	Unix, RBAC, ACLs, Least privilege, Trusted Extensions	chroot, Containers	IPFilter				13	2005-04-13
Windows Server 2003	ACLs, Privileges, RBAC	Win32 WindowStation, Desktop, Job objects	Windows Firewall,IPSec TCP/IP Filtering				10	2003-04-22
Windows XP	ACLs	Win32 WindowStation, Desktop, Job objects	Windows Firewall, TCP/IP Filtering, IPSec	(With NTFS)			2; 29	2007-02-23; 2002-09-02
ZETA	Unix						colspan="2"
STOP 6 / XTS-400	Unix, Multilevel security, Biba mandatory integrity, ACLs, Privileges, subtype mechanism	Multilevel security, Biba Integrity Model, subtype mechanism					0	-
z/OS	RACF	RACF, key-protected address spaces	z/OS IPSecurity	Optional	Yes (key-protected address spaces)	Yes	0	-

Comparison of known unpatched vulnerabilities is based on Secunia vulnerabilities reports with a severity of less critical and above. Updated automatically.
POSIX ACL support is included in Linux 2.6, but requires a file system capable of storing them (such as ext3, XFS or ReiserFS).
A jail mechanism is available separately in the Linux-VServer project, but is not integrated into any mainline Linux kernel.
The Exec Shield and PaX extensions provide NX emulation on x86 hardware. They are not yet integrated inside the mainline kernel but are available as patches or separate kernels
ACLs were added to Mac OS X beginning with version 10.4.
ACLs are available only in OS/2 Server versions with HPFS386 filesystem.
"Solaris Containers" (including "Zones") are a jail-type mechanism introduced with Solaris 10.
Zeta has full Unix file permissions, but the OS is single user, and users always run as superuser.
STOP 6 is certified under Common Criteria at EAL5+.
Additionally swap space may be encrypted during installation, uses memory based tmp file storage by default.
Through ZFS
Novell NetWare uses MSDOS to load itself in to memory and once it is running, MSDOS is not used and can be unloaded (it is a common misconception that NetWare "runs on top of MSDOS").
AIX use the PowerPC architecture which offer page-level protection mechanism. Since AIX version 5300-03 (5.3), this feature can be activated using the sedmgr command
FreeBSD can be built with ProPolice/SSP.
Available on XP sp2, 2003 sp1 and newer.
By default, software-enforced DEP helps protect only limited system binaries.