GRUB for DOS is a rebuild of the GNU GRUB boot manager for DOS, and can be run under real mode DOS. It also has many new features. It can be booted through BOOT.INI of Windows (grldr) and kexec of Linux (grub.exe). It can directly boot NTLDR (WindowsNT/2K/XP), IO.SYS (Windows9x/Me) and KERNEL.SYS (FreeDOS). The disk emulation feature is another enhancement over GNU GRUB, and can be used to run legacy DOS/Windows9x systems with floppy or hard disk images.