Please note that the website is aguslrs and has not been updated to the current state of this fork.
This is a project that contains a collection of GRUB files and scripts that will allow you to create a pendrive capable of booting different ISO files.
Visit the project's website for more information. (Again, this might be a little out of date or atleast not contain information about all there is in this fork)
This is a fork of aguslrs Multiboot USB, this fork adds more distros and is not quite as dead (I don't work on it every day, but I will still check on it once in a while.)