SparcOS was an awesome unix. Linux was respectable as well, but the hardware story in 2007 was much more shitty. Hardware vendors pretty much ignored linux, going for windows as I recall.

So if you just wanted a good Unix environment, SparcOS was it.

Java/ZFS were both Sun products, and we're still using them today. Just not SparcOS. Sun tried with Project Indiana, but they were getting outpaced by Linux and the open source movement.