was the version of the
UNIX Operating System developed by
Sun Microsystems for their workstations and server systems until the early
1990s . This was based on
BSD UNIX with some additions from UNIX
System V in later versions.
was based largely on 4.1BSD and released in 1982. '''SunOS 2.0''', released in 1985, used
4.2BSD as a basis and introduced a virtual filesystem (VFS) layer and the
NFS protocol. '''SunOS 3.0''' coincided with the launch of the
Sun-3 series in 1986 and incorporated various utilities from System V. '''SunOS 4.0''', released in 1989, migrated to a
4.3BSD base, introduced a new
Virtual Memory system,
Dynamic Linking and an implementation of the System V STREAMS I/O architecture.
SunOS 1 and 2 supported the
Sun-2 series. SunOS 3 supported Sun-2 and Sun-3 series systems; there was also a preliminary
Sun-4 release of SunOS 3.2. 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 architectures.
In the early 1990s Sun replaced the BSD-derived SunOS 4 with a version of UNIX
System V Release 4 , which they named
Solaris 2 . SunOS 4 was then
Retroactively Named "Solaris 1" in Sun marketing material.
The last release of SunOS 4 was 4.1.4 (Solaris 1.1.2) in 1994. It supported
SMP on some machines, but it had only a single lock on the kernel, so only one
CPU at a time could execute in the kernel. The
Sun-4 ,
Sun-4c and
Sun-4m architectures are supported in 4.1.4,
Sun-4d and
Sun-4u are unsupported.
GUI environments bundled with earlier versions of SunOS included SunTools (later
SunView ) and
NeWS . In 1989, Sun released
OpenWindows , an
OPEN LOOK -compliant
X11 -based environment also supporting SunView and NeWS applications. This became the default SunOS GUI in Solaris 1.0 (SunOS 4.1.1). Solaris 2.5 introduced the
CDE desktop.
Confusingly, the core of the Solaris operating environment (Solaris 2 onwards) is identified as despite its very different origins compared to previous SunOS releases.
The SunOS 5 minor version included in Solaris releases corresponds to the minor (up to Solaris 2.6) or major (Solaris 7 onwards) Solaris version number. For example, Solaris 2.4 incorporated SunOS 5.4 and the latest Solaris release, Solaris 10, runs on SunOS 5.10. Solaris
Man Page s are labeled with SunOS, and the startup sequence displays it, but the term "SunOS" is no longer used in Sun marketing documents.
