SunOS 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.
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.
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 pages are labeled with SunOS, and the startup console messages display it, but the term "SunOS" is no longer used in Sun marketing documents.
BSD | Sun software | Unix