YUMI (Your Universal Multiboot Integrator) is a free and open-source software that allows users to create bootable USB drives for multiple operating systems and tools. Its most important feature is the ability to add multiple ISO files to a single USB drive, allowing users to easily switch between different operating systems and tools without the need for multiple USB drives. YUMI also supports persistence, which allows users to save their data and settings on the USB drive and use it across different computers. Additionally, YUMI supports a wide range of operating systems and tools, including Linux distributions, antivirus tools, system utilities, and more.