Create an .iso from a CD or DVD using Disk Utility
This is a really useful feature of Disk Utility. Insert your CD or DVD and wait for it to spool up. Launch the Disk Utility and you should see your recently inserted disk in the left column. Click on the disk, then select New Image from the program menu. This will bring up a “save as” menu. At the bottom of this menu are two drop-down menus. Select DVD/CD Master from the one labeled “Image Format:.” Select Save. Rename the saved file from *.cdr to *.iso.
The subsequent ISO can be burned or read on any platform.