I used it in production along together with Linux at a startup as it was a fairly robust Xen guest circa 2008-11. I was having a ton of stability issues with C

I used it in production along together with Linux at a startup as it was a fairly robust Xen guest circa 2008-11. I was having a ton of stability issues with CentOS and Fedora DomU on PV Xen with CentOS 5 as the dom0. For some reason NetBSD ran great as a DomU on the same Dom0 so I went with it. I liked how Postifx was the base MTA, and was able to configure a useful systems with pkgsrc pretty easy. The strongest case today is probably for embedded use. build.sh is unlike any other OS build system, you can happily do development of a firmware on a Linux or OS X machine for instance and splat out results for a target device. It's also one of the better choices for learning about OS development because of build.sh, small size, fairly clean codebase etc. And those skills are fairly transportable to Linux (which is a bit of a fire hose and probably not the easiest to start out on) or commercial operating systems like OS X or real time for a career path.