GRUB Legacy

Grub is the default bootloader on Gentoo. This article discusses  (slot zero) also known as "Grub Legacy". Version 2, now available in the testing tree, is completely reworked and fundamentally a different bootloader — see GRUB2.

Installation
Install grub with:

Specifying slot 0 will make sure grub:2 will not get installed on world updates, unless you specifically install it.