Originally, the hardware architecture was so closely tied to the Mac OS operating system that it was impossible to boot an alternative operating system. The most common workaround, is to <answer>boot into Mac OS and then to hand over control to a Mac OS-based bootloader application</answer>. Used even by Apple for A/UX and MkLinux, this technique is no longer necessary since the introduction of Open Firmware-based PCI Macs, though it was formerly used for convenience on many Old World ROM systems due to bugs in the firmware implementation.[citation needed] Now, Mac hardware boots directly from Open Firmware in most PowerPC-based Macs or EFI in all Intel-based Macs.
Which technique was once used to boot an alternate operating system than Mac OS?
boot into Mac OS and then to hand over control to a Mac OS-based bootloader application