When you power on your computer, the first software that runs is a bootloader that invokes the computer's operating system. GRUB, the GRand Unified Bootloader, is an integral part of many Linux systems. It starts the Linux kernel. Here's some background on GRUB, and some tips on installing and configuring the software.

GRUB was originally written by Erich Stefan Boleyn and is now part of the GNU project. The current production version is GRUB 0.9x, also known as GRUB Legacy. In 2002 the developers shifted their focus to GRUB 2 and stopped adding features to the legacy code, though it still receives regular patches and bug fixes. GRUB 2 remains a development version; most distributions still rely on GRUB Legacy.

GRUB is not dependent upon any operating system. It was written to conform with the Free Software Foundation's Multiboot Specification, which allows it to boot almost any operating system. In fact, it can boot multiple operating systems on computers that have more than one installed on their hard drives. Among GRUB's features:

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