So does Illumos and OmniOS - which are direct forks from the last opensource versions of Solaris. I played around with illumos a few years ago before getting into FreeBSD and it’s a lovely little operating system.

It actually does run on KVM! I spent yesterday trying to get it to work and found the trick was setting the chipset to i440FX, and putting every drive on the IDE bus.

Probably not a reasonable choice for any real usage though.

The specific mention of open source developers makes me think "more open source software that works on Solaris" might be part of it. Doubt it'll help much, but it might move the needle from "they still make Solaris?" to a "guess I'll make sure it at least builds" sort of state.

“not sure what Oracle is trying to achieve here“

Yeah, this seems weird.

Perhaps they aren't trying to achieve anything at all, and this opening is just the small visible part of some internal conflict where one participant used to advocate for a grand open source Solaris strategy. Resolved by giving that participant this partial opening as a token concession.

There is no internal conflict. This is Oracle you're talking about.

VirtualBox (owned by Oracle too) will work, and is free to download.

omnios and solaris11 works nicely on libvirt/qemu. there are even vagrant images available, see:

https://app.vagrantup.com/rbrunckhorst/boxes/solaris11.4

I assume it runs on virtualbox?

Yep:

https://www.oracle.com/solaris/solaris11/downloads/solaris11...