More details about the MH-USB: https://mostlyharmless.io/usb/
By default, the following operating systems are available for live boot or installation:
/OS/alpine-standard-3.15.0-x86_64.iso
/OS/debian-live-11.2.0-amd64-cinnamon.iso
/OS/devuan_chimaera_4.0.0_amd64_desktop-live.iso
/OS/Fedora-Workstation-Live-x86_64-35-1.2.iso
/OS/guix-system-install-1.3.0.x86_64-linux.iso
/OS/haiku-r1beta3-x86_64-anyboot.iso
/OS/LibreELEC-Generic.x86_64-10.0.1.img
/OS/manjaro-kde-21.2.1-220103-linux515.iso
/OS/netboot.xyz.iso
/OS/openmediavault_5.6.13-amd64.iso
/OS/openwrt-21.02.0-x86-64-generic-ext4-combined.img
/OS/proxmox-ve_7.1-2.iso
/OS/Qubes-R4.0.4-x86_64.iso
/RPi/2021-10-30-raspios-bullseye-armhf-lite.zip
/OS/systemrescue-8.06-amd64.iso
/OS/tails-amd64-4.25.img
/OS/trisquel-mini_9.0.1_amd64.iso
/OS/ubuntu-20.04.3-desktop-amd64.iso
/Tools/imager_amd64.AppImage
/Tools/ungoogled-chromium_91.0.4472.164-1.1.AppImage