Long ago in January, richard6121 started a thread in the VMware Forums suggestion box entitled Ability to run ESX as a Workstation guest. VMware’s own Petr confirmed that with just the right knob twiddling and the right chip, you could convince Workstation 6.0 to run ESX Server inside of it. The race was on and the next few months were filled with through-the-looking-glass moments (yes, it even works on Fusion) and probably a bit of actual work as well — you probably wouldn’t want to run your production servers on it, but it’s great for training, configuring, demos, and experimentation.

In June, the gentlemen behind the always-excellent unveiled their own whitepaper in this thread.

Now they’ve just released their follow-on paper in this thread:

I’ve written a follow up white paper to the Xtravirt "ESX3 on
Workstation 6" white paper, outlining the steps to install an iSCSI
Enterprise Target Server in a VM and configure your ESX3 VMs to use
this iSCSI storage for a ‘VI3 in a box’ configuration.

Great if you want to demo VI3 Enterprise features like
VMotion, HA and DRS without having demo server kit available – you can
run all of the required compenents on a single physical machine. This
will also run on well specced laptop for mobile demonstrations.