GRUB - Multiboot boot loader
EasyBCD - EasyBCD is NeoSmart Technologies multiple award-winning answer to tweaking Windows bootloader.
U-Boot - Das U-Boot (the Universal Bootloader) and Embedded Linux
Grub2Win - Safely dual boot Windows and Linux without touching the Windows MBR.
Apple - Available on iOS
LILO Boot Loader - LILO stands for Linux Loader, is a boot loader tool that is used to load Linux OS into memory.