Solaris, basically. Illumos was derived from the old OpenSolaris project. I don't know how much it's diverged, as I don't really follow this much. But that's more or less what it is.

From: https://docs.openindiana.org/misc/openindiana/#what-is-the-o...

> Why is it called OpenIndiana?

> OpenIndiana obtains its name from Project Indiana, an open source effort by Sun Microsystems (now Oracle Corporation) to produce OpenSolaris, a community developed Unix-like distribution based on Sun Solaris. Project Indiana was led by Ian Murdock, founder of the Debian Linux Distribution.

(I never understood the naming either)

But here's an ArsTechnica article from 2007 talking more about those origins from back when Sun was still trying to win back marketshare from Linux. It had long since lost that war, but was still trying to stay relevant.

https://arstechnica.com/uncategorized/2007/07/understanding-...

Illumos based OS's have been kicking around a lot longer than I anticipated.

There is OmniOS[1] as well, fits next to OpenIndiana.

https://omnios.org.

I have also used SmartOS, which imports KVM from Linux.

It is odd to boot it and see sendmail running from my native ksh93 root login.

https://www.tritondatacenter.com/smartos

https://en.wikipedia.org/wiki/SmartOS

It (Solaris) was also the origin of ZFS, if I'm not mistaken.

I’m of the opinion that the acquisition of Sun by Oracle was the worst possible outcome; it guaranteed that Solaris would decline.

I think a lot of decisions that eventually lead to the Oracle buyout were all pretty bad and Oracle itself being where good ideas go to die. As bad as MS is at extracting value out of its windows users, Oracle seems to fleece it's enterprise customers far, far worse. I don't think I would ever choose Oracle or IBM for anything.

It would be interesting to see a little more diversity in common operating systems in the wild though. Linux has pretty much taken over the server space, and iOS/Android have split the more common usage outside that, with what's left of desktop still mostly Windows.

I still think there's opportunity for something like Flutter as a cross-platform library that actually works with multiple backing languages.

It still is!

At Oxide, we have our own illumos (in my understanding, you're supposed to lowercase the i) distribution, discussed on HN a while back https://news.ycombinator.com/item?id=39178521

OI uses IPS packaging, which is the same packaging used by Solaris 11 (some find it over engineered). Tribblix, on the other hand, is also an illumos-based distro but is based on Solaris 10 (and prior’s) SVR4 packaging which is managed via a utility called “zap”.

Both are good distributions, but I strongly encourage you to try Tribblix if OI is problematic; for whatever reason the latest OI installers do not seem to include the same amount of driver support as Tribblix, in my experience.

https://docs.openindiana.org/misc/openindiana/ looks like what you wanted, was not straightforward to get there from the homepage.