[AlexanderDhoore]

"Unfortunately, even though Macs use a variant of EFI (an earlier version of what's now called UEFI), they apparently can't cope with multi-catalog CDs, and simply refuse to boot them. This left us in rather a quandary: we needed to support UEFI systems, but we didn't want to drop support for Macs either.

I therefore created the amd64+mac CD images, which are exactly the same as the amd64 images except that they only support BIOS booting. Macs are happy to boot these in their BIOS emulation mode." [1]

TL;DR There is no difference... Normal CDs just won't boot on Macs.

[1] http://askubuntu.com/questions/37999/what-is-different-about...

[homosaur]

OHHHHHHH bootable. I'd never actually tried that as I've always installed in a VM. Now that makes sense as to why the Mac version wouldn't work when I tried it in a VM.