Sun Microsystems has long been known as a company that turns out first-rate, well-engineered software and hardware. Many former Solaris administrators and users still mourn the day their reliable Sun boxes and Solaris operating systems were taken away from them and replaced by the upstart and vastly inferior Microsoft Windows. The old, proprietary Unixes have been in a long, slow decline for many years anyway: They are expensive, run on expensive hardware, do not have binary compatibility with each other, and have not kept up with the times.
Except Solaris. In 2005, Sun made a bold move and released Solaris free of cost, under an open source license. And not only Solaris, but all of its server-side hardware as well. The latest Solaris (version 10) is chock-full of advanced goodies like the ZFS filesystem, DTrace, Containers and an overhauled networking stack with support for all the latest protocols plus considerable performance improvements. I don't remember an operating system last released with so many big new features.
Of course, Sun continues to push Java as something vitally necessary and breathlessly exciting. Most folks are more blasé than breathless. Installation is rather rocky; in fact, the word "sucks" get used a lot. Expect to spend a bit of time on it.
Once Solaris 10 is installed it's a whole different story. Old timers who recall the "Slowlaris" days won't recognize the new, speedy Solaris. It performs like a champion, to the point that users should notice a significant difference over other operating systems and even the olden Solaris days.
So who should give Solaris 10 a try? Any user who has supported hardware and applications: home users, power users, developers, and hardcore, rough-n-tough server administrators. It runs on both Sun and x86 hardware, but x86 support is still rather limited, so be sure to check the hardware compatibility lists first. There are enough differences between Solaris, Linux and other Unixes that you might want to pretend you're starting from scratch, so that old habits don't get in the way.
Visit Sun.com for downloads and more data sheets, whitepapers, tutorials and tips than you'll ever be able to use. BigAdmin.com and The Blog of Ben Rockwood are full of useful real-world information and help. BlastWave.org is trying to bring Solaris package management into the 21st century.