After Oracle effectively neutered the OpenSolaris project, many spin-offs of the public source code popped up, like oh-so-many mushrooms in a fallow field.  Many short-lived derivatives have come and gone, and there have been some surprising changes in the ecosystem.  I decided that it was time for a re-evaluation of the available variants.

It should be noted that the goal here is to compare these various OpenSolaris spin-offs against each other, not against other FOSS operating systems.  As such, I focus primarily on the quantifiable traits that differentiate them.  Things that they all have in common are omitted.  Traits like the software packaging system in use are not quantitative, only qualitative, so that's not of interest here (though it is a serious consideration for usability).  Similarly, capabilities relative to other operating system families like GNU/Linux, the BSDs, or Windows are outside the scope of this comparison.

In considering each variant, I looked at the following attributes:

  • Download ease - could a download be quickly and readily obtained from the variant's main page?
  • Version maintenance - has an official release been made within the last 365 days?
  • Documentation availability - could installation and setup documentation be found easily from the download page?
  • Documentation maintenance - does the available documentation cover up to the most recent official release?
  • Boot capability - does the variant support EFI boot on x86-64 "out of the box"
  • Disk label recognition - can the variant read GPT disk labels, at least in a non-boot capacity?
  • VirtIO support as a KVM guest - VirtIO block devices, network devices, memory ballooning, CPU hotplugging, and serial devices are all considered
  • Ability to act as a KVM host - pretty self-explanatory, all via the Joyent illumos-kvm project
Each attribute affords a total of one point- all are boolean, one or zero, with the exception of VirtIO support, with each of the five components counting for 1/5 of a point.  Stock Oracle Solaris 11.2 has been included for reference, though it is (by definition, at least) not an "OpenSolaris derivative."  The total ranking is then expressed as a percentage and a letter grade.  Here is the summary (full results available in this PDF):
Name TOTAL Grade Version Tested Most significant perk Most significant deficit
SmartOS 85% B 3783 Cloud friendliness No EFI boot
OpenSXCE 85% B 2014.05 Hardware support No EFI boot
OmniOS 85% B 151012 Compat. with Oracle Solaris No EFI boot
Oracle Solaris 65% D 11.2 EFI boot support No KVM support
DilOS 60% D 1.3.7 Ease of migration from Linux Lack of documentation
OpenIndiana 58% F 151a Compat. with Oracle Solaris Outdated builds
Dyson 58% F 1327 Ease of migration from Linux Lack of documentation
illumian 58% F 1 Ease of migration from Linux Outdated builds
Belenix 0% Inc. N/A N/A Website down
Non-Solaris Comparisons:          
Fedora 100% A 21    
FreeBSD 88% B 10.1   No KVM host support

I've included the same criteria applied to Fedora 21 and FreeBSD 10.1 for reference only- their capabilities aren't intended to be a part of this analysis.
As we can see, the clear leaders under this evaluation are OpenSXCE, Joyent's SmartOS, and OmniTI's OmniOS, all with a "B" grade at 85%.  Next with a "D" grade are stock Oracle Solaris and DilOS.  OpenIndiana, OS Dyson, and Illumian are close behind those two, though still technically with failing grades.  Belenix could not be evaluated due to the main website being unavailable- it's apparently in the process of moving to a GitHub-hosted website, and the move is not yet complete.

While there are a few stars shining out in this bunch, to somebody who remembers the "golden days" of the OpenSolaris project, I can only reach one conclusion: the FOSS Solaris movement has been fractured.  The best contenders receive a "B" on the evaluation, and two of those three have significant backing from large IT companies.  It seems that no single OpenSolaris-derived project has the community backing required to bring it to premier status, and I'm concerned that without such support, the only FOSS System V derivative may be quickly headed towards fork-and-die oblivion...