*.dmg is a disk image file format widely used on Macintoshes for software distribution.

*.dmg is a disk image file format widely used on Apple Macintosh computers for software distribution. Questions about the creation, distribution, use and maintenance/repair of these files should be tagged with this. dmg files may be of any size and supersede previous file formats such as *.img, which were specifically images of floppy disks. For more information, see Wikipedia: http://en.wikipedia.org/wiki/Apple_Disk_Image