@silverwizard i'm far from an expert on this but wikipedia claims solaris containers/zones were circa 2005. i also kinda remember hearing about them at the time. rfork and plan9 namespaces predated me by far and according to this (http://doc.cat-v.org/plan_9/4th_edition/papers/names) they were published around 1993. :). of course the scope of isolation that they offer is different. and you can argue that solaris was a "production system". Plan9 just seems to have tried to address the problem in its design.