At the end of work today, I had a fully-functional OpenSolaris machine running under VirtualBox.
I have tried, at various points in time, to keep a Solaris x86 machine around — "But, Mom! It followed me home! Honest!" — but in the end, I always wiped it. That is, if I ever got the installation finished. Solaris has not been an easy installation.
This wasn't real. This was virtual. A virtual ISO sat in a fake CD-ROM drive and filled a phony chunk of memory full of OpenSolaris. I clicked "GO", moved to another desktop and beat my head on Catalyst and MySQL for a little while. Then, I moved back to the desktop and clicked OK, and it was done. I had my first stab at Solaris package management trying to install the "Guest" packages.
First time I sat behind a Solaris box, I was using CDE. Ever use CDE? CDE is the reason people started looking in to window managers. So they could get away from it! OpenSolaris comes with Gnome, and it's nice. Nice like the Gnome that comes with Ubuntu. And they're both Live CDs.
If the OpenSolaris user experience is, within Δ, the Ubuntu user experience, why use OpenSolaris? You want to integrate into a huge Sun environment. You develop in Java or otherwise want to have your Sun-based development environment. You're used to Sun. Or you wish to prove your manhood by grappling with the OS that was the go-to Unix when Linus was in high school.
I almost have a use for the similar XP install on my desktop. I don't really have one for OpenSolaris yet. So, what do I use it for?