Linux VServer allows the running of multiple linux distributions in a secure and compartmentalised manner inside a running 'parent' Linux system. For more information, see the official home of this project.
I've used Linux VServer heavily both during my employment at DSVR and for personal projects. For the latter I built a crufty Slackware arrangement for building virtual servers, mainly because of the simplicity of the distribution. Now I'm attacking Fedora to achieve the same end, as although the Slackware method served a purpose, it's far less easy to maintain.
Because I couldn't find any 'official' Fedora RPMs for the VServer enabled kernel, or the util-vserver tools that would build or work, I've rolled my own with a bit of tweaking. I've provided them for download here in the hope that they'll help someone else get a VServer system up and running on Fedora
The following RPMs are based on kernel-2.6.12-1.1447_FC4.src.rpm as provided by the Fedora project, and have been patched using patch-2.6.12.4-vs2.0.diff from the Linux-VServer stable release. A handful of patch hunks fail due to conflicts between Fedora patches and VServer patches, and I merge those back in by hand before generating a working diff which gets included in the RPM.
These are built from util-vserver-0.30.208.tar. The only tweak required is to stop them depending on the xalan-j package, as FC4 provides xalan-j2 instead.