GNU GRUB is a Grand Unified Bootloader. GNU GRUB project, which is a rewrite of GRUB, is alive and in development. GRUB is to merge sources PUPA to create the next generation of GNU GRUB. A mailing list and a wiki was set up to discuss the development of GRUB.Multiboot specification is a protocol between a boot loader and an OS kernel. Because this specification is generic, you can use the protocol in your boot loader and / or your own open source operating system. Follow this link for more details.