For the Raspberry Pi, there are two alternative installation methods that allows multiboot. Some users want to dual boot Lakka and OpenELEC. NOOBS is the prefered method.
Works for RPi1, RPi2, RPi3 and RPi4.
Works for RPi1 and RPi2.
Works for SolidRun hardware, the imx6 hummingboard and cubox-i. They support Lakka officially.
If you want to install Lakka on a PC that does not support USB booting, but has a CD drive.
PlopKexec is a Linux Kernel based boot manager for autodetecting and chainloading Linux distributions from USB and CD/DVD. It works even if no Bios USB support is available.