I've not been that long with *nix OS so my interest in OpenSolaris doesn't date much back. Mainly it came out of the combination of the great ZFS filesystem and COMSTAR Framework (Common Multiprocol SCSI Target). I will post later once why we opted for NexentaStor at work. This is a commercially supported variant of ON source made by Nexenta Systems. We knew that OpenSolaris had an uncertain future but nonetheless the FUD was outweight by the advantages.
Time has been turbulent - and still is - around OpenSolaris and I try to compile for even more outsiders than I am where you might want to go if you want to play or even deploy something productively on ZFS. As you, might certainly know, the OpenSolaris distro, "Project Indiana" is dead, a 2010.x release has and will never happen. Oracle has changed to more closed development model. They announced to release allready CDDL'ed source after major release - but ATM we don't know if that is really going to happen.
So where can I go then if I don't want or can't go Oracle?
Some people believe in a future of the ON code without Oracle releasing bi-weekly putbacks. Nexenta Systems' Garret D'Amore started an effort to continue core ON development with the main task of replacing all remaining closed source parts of OpenSolaris code like internationalization of libc, some crypto and drivers. This Project called IllumOS and backed by an independent foundation - they try to omit the errors of dependency like OpenSolaris had. As Jörg Möllenkamp at Oracle has posted on his blog: It is not because of idealism this happened. Businesses have built their products by using OS/Net source code from Oracle-Sun. Theyre businesses depends on ON source technologies: E.g Nexenta Sysems heavily uses ZFS and COMSTAR for it's Storage Appliance OS and Joyent uses an own Distribution of ON Kernel and NetBSD for its cloud services. They knew Sun could die or turn the tap of to code and fixes.
So what is IllumOS in short?
IllumOS is a project that aims at replacing closed source parts in OpenSolaris to create a fully open OS/Net source and later continue core development - eventually integrating Oracle source releases to keep up the track. It's definitely not aimed at replacing any distribution efforts. It's comparable as Linux' kernel.org but with lot's more like userland applications. You can compile IllumOS and boot it but you have to do it yourself. (yet)
OK, but I need a distro!
Happily, there are some you can choose from. Diversity and some competition helps! These aren't all but some of the most important.
Tries to make a possible upgrade path for OpenSolaris users by compiling last source (147) of Oracle's ON. This is a IPS-Packaging Distro where you can upgrade your OpenSolaris release or latest developer build (134) from. At this moment, this is a developer release including latest ZFS and zPool versions. But it does not include IllumOS ON at the moment but will. This project is under the hood of IllumOS foundation lead by Alasdair Lumsden.
What is SchilliX?
This distribution created in major parts by Jörg Schilling (Schilly) owns the legacy of being the first compiled distribution of ON code even before former Sun first released first "Indiana" Distribution called 2008.05. Since Schilly prefers Sun's userland over GNU tools they are the primary ones unlike OpenSolaris and OpenIndi. It will also be based on IllumOS but atm it also incorporates Oracle's last ON code "snv147".
Hey but I need something more stable and cleanly installable!
Nexenta Systems creates its own distribution with the community called Nexenta Core Plattform. Since the Nexenta guys have background in Linux iSCSI they happen to like Debian's apt packaging and GNU environment. Nexenta's open source distro is the base for their commercial NexentaStor product which essentially adds storage-specific Management tools (which are proprietary) and can be expanded with commercial plugins for easy replication, VM storage management and lots more.
Since it is aimed to be stable and Sun's 134 codebase meant to lead to stable OSol 2010.x release Nexenta decided to base it's distro on this release. Nexenta has incorporated lot's of patches and fixes from later source drops and thus has matured the not-so stable 134b source code. Am I wrong if I compare it with a RHEL or Debian stable in the Linux world? You won't find the most recent code in Nexenta, even the RC releases happen to be quite stable.
What you get is a ON married with GNU userland and Debian's apt. Since it uses Sun's libc unlike what Debian GNU/kFreeBSD has done with GNU libc and the FreeBSD Kernel the packaging needs more adaptation and sometimes NCP specific patches. It feels like a Debian-based distro but as Debian and Ubuntu user you can get quite familiar fast. It's the most GNU-ish distro since it uses Ubuntu's 8.04 LTS packages. This is absolutely sufficient for a server distro. Also at default there is no UI since Nexenta aims NCP to be their minimal base for their commercial offering. You can install a GNOME on it but it's not the primary aim. Since Nexenta is backing IllumOS with monay and developers (i.e. Garret D'Amore) future NCP versions will be based on IllumOS core.
Last but not least there is FreeBSD's ZFS port which includes zPool 15 in latest 8.1 and can be experimentally patched to zPool 28 at your own risk.
This is certainly my personal overview but maybe this can help you in deciding where to go 🙂