What is "ipxe"

iPXE is an open-source implementation of the Preboot eXecution Environment (PXE) client firmware and bootloader, created in 2010 as a fork of gPXE. It can be used to enable computers without built-in PXE support to boot from the network, or to extend an existing PXE client implementation so it supports additional protocols.

While standardized PXE clients use TFTP to transfer data, non-standardized iPXE client firmware adds the ability to retrieve data through other protocols, including HTTP, iSCSI, ATA over Ethernet (AoE), and Fibre Channel over Ethernet (FCoE). Also, on supported hardware iPXE firmware can use a Wi-Fi link rather than requiring a wired connection. iPXE firmware cannot be considered as a "drop-in" replacement for PXE firmware.