Back in 1987, AT&T and Sun announced that they were working together to release a new release of UNIX, merging the two most commonly used variants at the time – BSD and System V. This new UNIX release would be called UNIX System V Release 4 – SVR4.
In 1991, Sun said that they were replacing their existing UNIX OS, SunOS, with a new release based on SVR4. SunOS was based on BSD and Sun were starting to encounter issues with that codebase, and so with an eye to the future Sun announced Solaris 2.
SunOS was then renamed Solaris 1, and each Solaris variant was composed of the operating environment (Solaris 2.6, Solaris 7, Solaris 10) and it’s related kernel (SunOS 5.6, SunOS 5.7, SunOS 10). The reason for this strange branding was that Solaris would refer to the complete operating environment, which included the window manager and other applications.
Solaris now uses a common codebase for both SPARC and x86 versions. Previous versions had officially been ported by Sun to the PowerPC and Itanium processors. Solaris is now one of the most common UNIX variants, thanks to it’s power, scalability, and many new technologies Sun include with each release.
With the announcement of OpenSolaris, Sun have completed the task of open sourcing a powerful high end UNIX, allowing even the smallest UNIX consultancy to build a cost effective UNIX infrastructure.