TOAST is a file extension used for CD or DVD disc image files. TOAST files are compatible only with Mac OS X systems and using them on different systems may cause problems.

Structure of TOAST file format is similar to ISO, the image file standard, but contains additional Mac OS X-specific information. TOAST files can be converted into ISO in order to open access contents on Windows systems. This solution may not guarantee full-compatibility, but should solve the problem with opening TOAST files on systems other than Mac OS X.