[NexRebular]

Well if we go to that, illumos, or rather Solaris had zones even earlier in 2004 or so.

I run illumos and *BSD (FreeBSD servers, OpenBSD on SPARC and network appliances) in production mostly because they just work(tm). They are battle tested pieces of wonderful software engineering with great documentation and community support (ymmv) out of the box. SmartOS has replaced most of our linux and vmware based hypervisors at $work and they are just so much nicer to administer in the simplicity and design compared to the others. In addition we have a Triton cluster as our primary on-prem cloud service.

tl;dr They have proven to be a lot nicer to run as well as more dependable than the alternatives.

[arpa]

Thank you for giving me stuff to read upon. Cheers!