SunOS (what the hell is with their versioning anyhoo?)

Since you were dumb enough to ask....

The SunOS kernel version number in version 4 was the same as the marketing release number, 4.1.4, for example. When they moved to version 5, there were a number of changes. The big one is that they moved from BSD to SystemV, with a small smattering of BSD stuff thrown in. At the same time, marketing decided that they needed a new product, and called the whole bundle -- kernel, OS, windowing system, etc. -- Solaris. Since they were still supporting SunOS 4.whatever, and didn't want to orphan it, they retroactively named SunOS 4 Solaris, too. So now they have two versions of Solaris. SunOS 4 was Solaris 1 and SunOS 5 was Solaris 2. Of course, they needed minor revisions for Solaris 2, so they used the minor version number from the kernel. So Solaris 2.5 was SunOS 5.5 plus the rest of the OS plus XWindows, etc. When they got to what would have been called Solaris 2.7, marketing decided they needed another change. They felt that the numbers weren't moving fast enough. So they decided to drop the 2. part of Solaris. So now Solaris goes by just the SunOS 5 minor revision number, so Solaris 8 is SunOS 5.8 plus everything else.

Colloquially, Solaris 2 is called Solaris and Solaris 1/SunOS 4 is called SunOS.

Hope that clears things up for you.