I'm looking for a lightweight virtualisation / heavyweight chroot type solution. The virtualisation space has just exploded in recent times and i'm not convinced i'm aware of all the options.

I'm looking for something along the lines of BSD Jails or Solaris Zones. I know of UML from way back, but my experience of it then was not all that great: slow & high resource usage.

I was sure there used to be a project called Linux Virtual Server -- and it was pretty much what i was looking for. Either i have the name wrong, or the project has since folded (was a while back i came across it).

Any pointers greatly appreciated. I should probably say i'm aware of the following: User Mode Linux, Xen, Vmware, VirtualBox, Qemu.