pxe-boot is a PXE boot configuration of a Red Hat kickstart environment and another PXE boot environment of a recovery console. The Red Hat kickstart is just the standard Red Hat install boot disk (ES3.0), but it does not come with the installation files, just the install environment. The recovery console is an edited Gentoo environment with raidtools, parted, partimage, lilo, grub, and a slew of other handy recovery tools.
