SunOS
Screenshot and graphical interface of SunOS 4.1
Developer	Sun Microsystems
OS family	Unix (BSD/SVR4)
Working state	Historic; now marketed asSolaris
Source model	Closed source
Initial release	1982; 44 years ago (1982)
Latest release	4.1.4[1] / September 1994; 31 years ago (1994-09)[2]
Supported platforms	Motorola 680x0,Sun386i,SPARC
Kernel type	Monolithic kernel
Default user interface	SunView,OpenWindows
License	Proprietary (binary only)
Succeeded by	Solaris

SunOS is aUnix-brandedoperating system developed bySun Microsystems for theirworkstation andservercomputer systems from 1982 until the mid-1990s. TheSunOS name is usually only used to refer to versions 1.0 to 4.1.4, which were based onBSD, while versions 5.0 and later are based on UNIXSystem V Release 4 and are marketed under thebrand nameSolaris.

SunOS 1 only supported theSun-2 series systems, includingSun-1 systems upgraded with Sun-2 (68010) CPU boards. SunOS 2 supported Sun-2 and Sun-3 (68020) series systems. SunOS 4 supported Sun-2 (until release 4.0.3), Sun-3 (until 4.1.1),Sun386i (4.0, 4.0.1 and 4.0.2 only) and Sun-4 (SPARC) architectures. Although SunOS 4 was intended to be the first release to fully support Sun's new SPARC processor, there was also a SunOS 3.2 release with preliminary support for Sun-4 systems.

SunOS 4.1.2 introduced support for Sun's firstsun4m-architecturemultiprocessor machines (theSPARCserver 600MP series); since it had only a singlelock for the kernel, only oneCPU at a time could execute in the kernel.

The last release of SunOS 4 was 4.1.4 (Solaris 1.1.2) in 1994. Thesun4,sun4c andsun4m architectures were supported in 4.1.4;sun4d was not supported.

Sun continued to ship SunOS 4.1.3 and 4.1.4 until December 27, 1998; they were supported until September 30, 2003.

In 1987,AT&T Corporation and Sun announced that they were collaborating on a project to merge the most popular Unix flavors on the market at that time: BSD (including many of the features then unique to SunOS),System V, andXenix. This would becomeSystem V Release 4 (SVR4).^[8][3]

On September 4, 1991, Sun announced that its next major OS release would switch from its BSD-derived source base to one based on SVR4. Although the internal designation of this release would beSunOS 5, from this point Sun began using the marketing nameSolaris. The justification for this new "overbrand" was that it encompassed not only SunOS, but also theOpenWindows desktop environment andOpen Network Computing (ONC) functionality.

Even though the new SVR4-based OS was not expected to ship in volume until the following year, Sun immediately began using the newSolaris name to refer to the currently shipping SunOS 4 release (also including OpenWindows). Thus SunOS 4.1.1 was rebrandedSolaris 1.0; SunOS 5.0 would be considered a part of Solaris 2.0. SunOS 4.1.x micro versions continued to be released through 1994, and each of these was also given aSolaris 1.x equivalent name. In practice, these were often still referred to by customers and even Sun personnel by their SunOS release names. Matching the version numbers was not straightforward:

Today, SunOS 5 is universally known asSolaris, although theSunOS name is still visible within the OS itself – in the startup banner, the output of theuname command, andman page footers, among other places.

Matching a SunOS 5.x release to its corresponding Solaris marketing name is simple: each Solaris release name includes its corresponding SunOS 5 minor version number. For example, Solaris 2.4 incorporated SunOS 5.4. There is one small twist: after Solaris 2.6, the "2." was dropped from the Solaris name and the SunOS minor number appears by itself. The latest Solaris release is namedSolaris 11 and incorporates SunOS 5.11.

Beginning with SunOS 1.0, the Sun Window System provided aGUI called Suntools,^[9] layered on top of lower-level windowing and bitmap libraries;^[5] this was renamedSunView in SunOS 3.0.^[10] Sun then developed a novel window system calledNeWS that used and extended thePostScript language and graphics model. In 1989, Sun releasedOpenWindows, anOPEN LOOK-compliantX11-based environment which also supported SunView and NeWS applications. This became the default SunOS GUI in SunOS 4.1.1.^[11]

• Comparison of BSD operating systems
• Comparison of operating systems
• Illumos
• OpenSolaris
• OpenIndiana
• Solaris (operating system)
• JavaOS
• Unix wars

• The Sun Hardware Reference (Overview)
• SunOS & Solaris Version History at theWayback Machine (archived June 2, 2008)
• An Introduction to Solaris – a sample chapter fromSolaris Internals: Core Kernel Architecture by Jim Mauro & Richard McDougall, Prentice-Hall, 2000. (PDF)
• Info on SunOS from OSdata (last updated February 17, 2002)
• Initial Solaris announcement

• Berkeley Software Distribution
• Discontinued operating systems
• Sun Microsystems software
• UNIX System V
• X86 operating systems
• 1982 software

• Articles with short description
• Short description is different from Wikidata
• Webarchive template wayback links