&gt; Great is a relative term. But, can you name an OS, especially a UNIX, that is better in the general case? By &quot;general case&quot;, I mean, good for just about anything, even if there&#x27;s something better for some niche or role. Also, take into account the world we live in: More computing happens on servers and phones than on desktops and laptops; and judge the OS based on how it&#x27;s doing in those roles.<p>Okay then, SmartOS. Why is an exercise left for the reader, because it would just take too much and too long to list and explain all the things it does better, faster and cheaper than Linux in server space; that&#x27;s material rife for an entire book.<p>&gt; can you honestly say you enjoyed working on it more than Linux?<p>Enjoyed it?!? Love it, I love working with Solaris 10 and SmartOS! It&#x27;s such a joy not having a broken OS which actually does what it is supposed to do (run fast, be efficient, protect my data, is designed to be correct). When I am forced to work with Linux (which I am, at work, 100% of the time, and I hate it), it feels like I am on an operating system from the past century: ext3 &#x2F; ext4 (no XFS for us yet, and even that is ancient compared to ZFS!), memory overcommit, data corruption, no backward compatibility, navigating the minefield of GNU libc and userland misfeatures and &quot;enhancements&quot;. It&#x27;s horrible. I hate it.<p>&gt; The userspace on Solaris was always drastically worse than Linux,<p>Are you kidding me? System V is great, it&#x27;s grep -R and tar -z that I hate, because it only works on GNU! Horrid!!!<p>&gt; But, Linux brought us a UNIX we could realistically use anywhere, and at a price anyone could afford.<p>You do realize that if you take an illumos derived OS like SmartOS and Linux, and run the same workload on the same cheap intel hardware, SmartOS is usually going to be faster, and if you are virtualizing, more efficient too, because it uses zones, right? Right?<p>It&#x27;s like this: when I run SmartOS, it&#x27;s like I&#x27;m gliding around in an ultramodern, powerful, economical mazda6 diesel (the 175 HP &#x2F; 6 speed Euro sportwagon version); I slam the gas pedal and I&#x27;m doing 220 km&#x2F;h without even feeling it and look, I&#x27;m in Salzburg already! When I&#x27;m on Linux, I&#x27;m in that idiotic Prius abomination again: not only do I not have any power, but I end up using more fuel too, even though it&#x27;s a hybrid, and I&#x27;m on I-80 somewhere in Iowa. That&#x27;s how I&#x27;d compare SmartOS to Linux.