OpenIndiana is [wikipedia.org] a free and open source Unix operating system derived from OpenSolaris and based on illumos.
Curmudgeonly software reviewer Dedoimedo AKA Igor Ljubuncic reports [dedoimedo.com]
I find the test today somewhat sad. Sure, I did accomplish what I needed, but it gave me no joy, and no hope that this operating system can even even remotely compare against any Linux. Even CentOS is lightyears ahead. In the server environment, it may have its uses, but it completely misses the mark on the desktop.
Package management, applications, it all just feels raw, alien, unfriendly. What do you do if there are problems with drivers, or hardware? Where do you find the latest apps, and this isn't just an act of mercy by a volunteer? What about compatibility on actual hardware. The fact I was not willing to commit my test laptop also tells something.
You can master and tame OpenIndiana, to a level. But it is mostly a futile exercise in obstinacy. All of the stuff we've done above are more or less a given in Linux, and have been so since about 2007. It's like driving an old car and trying to match its abilities to new, modern technology. Unless you're into antiques, it's not really worth it.
The worst part, I guess, isn't the specifics. That can be sorted. It's the absolute lack of progress since 2011, in the desktop space. Underneath it may be wonders, but if you cannot use the system, then it's worthless. Lots of the stuff from the previous version have been removed [or] made less accessible, but we get nothing new in return. So it is nerdier and harder than before, and that's a grim sign of a future that has no place on the desktop. This seems to be true with other operating systems in this family, too. Just not worth the effort. Stick with Linux. Grade wise, 4/10.