BSDTalk 140 is an interview with Kristaps Dzonsons, author of Mult, a “instance multiplicity system”. It sounds similar to vkernels or Xen, though I’m sure there’s someone gritting their teeth at my generalizations.
A running description of activity related to DragonFly BSD.
It’s probably more similar to vserver/openvz in linux land.
http://mult.bsd.lv/docs-faq.xhtml seems to have the details.
It sounds very similar to Solaris’s Zones, but without a “host/guest” relationship.