While we dont know how Edgar "Gimli" Hucek did it yet, what we do know is that he appears to be the first to get Linux running on a Mactel.
It had been expected that porting Linux to a Mactel would happen relatively quickly, unlike, say porting Windows to the same hardware. But, although there were rumors that Red Hat engineers were working on it, the honor of getting there first goes to Hucek.
The first Linux to make the jump was Gentoo. This doesnt come as much of a surprise, since Gentoos Portage source-code based software distribution system makes it perhaps the most flexible and configurable of all the major Linux distributions.
To boot up, Hucek had to make modifications to Intels open-source elilo (extensible firmware interface Linux bootloader), which replaces the BIOS on Mactels, the Linux kernel and several drivers.
With this, Hucek has been able to "boot from a USB hard disk on the [17-inch] iMac Core Duo. We are using the hacked vesafb driver to inherit the bootloaders framebuffer, keyboard and a USB network card work."