Solaris Version Numbering

From Genunix

Each version of Solaris which Sun releases has three different version numbers. These are explained below.

SunOS Version

SunOS is what Sun Microsystems Inc calls all of the mainline operating systems it produces. SunOS 4 was based on BSD UNIX, while SunOS 5 was based on Berkeley System V Release 4 (also known as SVR4). What we now know as Solaris today is also called SunOS 5. The minor version number of SunOS gives the version number you will recognise from the Sun website, e.g. SunOS 5.10 is the same as Solaris 10. This is why running the uname command on Solaris will report that you have SunOS version 5.11.

Solaris Version

When Sun released Solaris, they went back and renamed SunOS 4 as "Solaris version 1". So the Solaris we know today is named "Solaris version 2". Old versions of Solaris 2.x were known by their 2.x name, e.g. Solaris 2.5 and Solaris 2.6. Solaris 2.7 was the first to be marketed as Solaris 7 - see below.

The Version Number "Joe Public" Uses

Since Solaris 7, Sun now uses a single version number to market each new version of Solaris. This helps make each new release of Solaris look like a bigger change, and has the handy side-effect of making the major version number much bigger, i.e. Solaris 10 sounds more mature than Solaris 2.10, to a CIO anyway. ;-)