GRUB - Multiboot boot loader
coreboot - coreboot is an extended firmware platform that delivers a lightning fast and secure boot experience...
Grub2Win - Safely dual boot Windows and Linux without touching the Windows MBR.
U-Boot - Das U-Boot (the Universal Bootloader) and Embedded Linux
PLoP Boot Manager - The PLoP Boot Manager is a small program to boot different operating systems.
Libreboot - Libreboot is a distribution of ...