toast is: Toast is an extension of Roxio Toast CD-DVD backup. Those files are opened by Roxio Toast.
It is a file that backed up by Roxio software. This format is used for the purpose of CD-DVD back up especially on the Machintosh computers
In Windows operating system, you can try to run those files with a compression file called 7-Zip. Also you are able to open those files by interchanging extension with ISO. And then you can open Roxio Toast with the assistance of a Cd burning software.
Toast File format viewers or openers
Toast File related links.