The ability to perform an ESXi Scripted Installation over the network has been a basic capability for non-Apple hardware customers since the initial release of classic ESX. However, for customers who run ESXi on Apple Mac Hardware (first introduced in vSphere 5.0), being able to remotely boot and install ESXi over the network has not been possible and customers could only dream of this capability which many of us have probably taken for granted.
Unlike traditional scripted network installations which commonly uses Preboot eXecution Environment (PXE), Apple Mac Hardware actually uses its own developed Boot Service Discover Protocol (BSDP) which ESXi and other OSses do not support. In addition, there are very few DHCP servers that even support BSDP (at least this may have been true 4 years ago when I had initially inquired about this topic). It was expected that if you were going to Netboot (equivalent of PXE/Kickstart in the Apple world) a server that you would be running a Mac OS X system. Even if you had set this up, a Netboot installation was wildly different from a traditional PXE installation and it would be pretty difficult to near impossible to get it working with an ESXi image. With no real viable solution over the years, it was believed that a Netboot installation of ESXi onto Mac Hardware just may not be possible.
tl;dr - If you are interested in the background to the eventual solution, continue reading. If not and you just want the goods, jump down a bit further. Though, I do think it is pretty interesting and worth getting the full context 🙂