Mac Linux USB Loader is an application that allows you to create bootable USB drives containing a Linux distribution that can boot natively on Apple's Macintosh computers using their EFI system, regardless of whether or not the selected distribution has UEFI support. It is available in English, Spanish, Traditional Chinese, and Greek. For information on the supported languages, or if you want to help translate, please see here.
Some Key Features
Mac Linux USB Loader has a number of key features:
Non-Destructive Install: (does not format your USB drive as long as it has a FAT32 filesystem).
Supports mainstream Linux distributions, such as Ubuntu, Linux Mint, Zorin, and more
Includes persistence support for Ubuntu-based distributions (for instructions on how to set it up, see this link)
Automatically detects all removable devices
Docs & Support
Sources of help for Mac Linux USB Loader are plentiful. Some sources include: