You can view the scripts that are embedded into the images here.
netboot.ipfs is a fork of netboot.xyz that uses IPFS gateway located in local network instead of internet-based CDN to get system images.
netboot.xyz is a convenient place to boot into any type of operating system or utility disk without the need of having to go spend time retrieving the ISO just to run it. iPXE is used to provide a user friendly menu from within the BIOS that lets you easily choose the operating system you want along with any specific types of versions or bootable flags.