Despite what it might seems at a first look, this is NOT a complicated thing.
The advantages are enormous… especially if you own a developer account: it would allows you to test the evolution of this awesome OS blended with great benefits of virtualization such as snapshotting.
Whatever is the reason why you wanna install Mavericks on your ESXi box, you’ll find here detailed instructions which have been tested and found working by me 😉
First of all, you need an important piece of software… and no, this software is not illegal, nor it could ruin your precious ESXi 5.1 installation. I’m talking about the mighty Unlocker for VMware by Donk, available from InsanelyMac (free registration).
This is a bunch of bytes which will enable your ESXi to boot a valid Mavericks image.