Multi-boot from a USB drive, even with UEFI support, using Easy2Boot portable
Easy2Boot is a free portable tool that lets you transform a USB drive into a multi-boot environment. Note that the program comes without a graphical interface; if you don’t like working with command lines, just ignore it.
Easy2Boot provides satisfactory documentation, which means that even if you are not familiar with command line arguments, you won’t face problems using it.
On Screen messages let you perform easily the task of transforming a USB drive into bootable media. A nice feature is that you need to format your drive only once, then just update the program, whenever an upgrade is available, and your media images, which are stored in their own directories to be used when you boot a machine.
Easy2Boot is a powerful and reliable tool to use if you are interested in USB bootable media, provided of course that a GUI is not absolutely necessary for you.