gummiboot!

rEFInd is a fork of the rEFIt boot manager for computers based on the Extensible Firmware Interface (EFI) and Unified EFI (UEFI). Like rEFIt, rEFInd is a boot manager, meaning that it presents a menu of options to the user when the computer first starts up, as shown below. rEFInd is not a boot loader, which is a program that loads an OS kernel and hands off control to it.

Like coreboot, libreboot is boot firmware intended as a free 'BIOS' replacement for your computer.

coreboot (formerly known as LinuxBIOS) is a free software project aimed at replacing the proprietary BIOS firmware found in most computers with a lightweight system designed to perform only the minimum of tasks necessary to load and run a modern 32-bit or 64-bit operating system.

rEFIt is a boot menu and maintenance toolkit for EFI-based machines like the Intel Macs. You can use it to boot multiple operating systems easily, including triple-boot setups with Boot Camp. It also provides an easy way to enter and explore the EFI pre-boot environment.

This is EFI-based bootloader for BIOS-based computers created as a replacement to EDK2/Duet bootloader.