It's a disk image format for Alcohol 120%. I ported over 2 UNIX apps (IAT and MDC2ISO) aaaages ago. Look for them (can google them) and see how you go. They can convert it to ISO for you.
Not sure if I had an Intel Mac when I ported IAT.
Also, my most common complaint was "IT DOESN'T WORK!!!" It really does, but it CAN'T work if you are using some corrupted/pirated image that you downloaded from Bit Torrent which is actually a Windows virus in disguise. I dropped support because I literally had thousands of pirates e-mailing me a day.