to Apple Inc. for their engineers to review. Crash Reporter has three modes of operations: Basic — The default mode. Only application crashes are reported, and the dialog does not contain any debugging information. Developer — In addition to application crashes, crashes are also displayed for background and system processes. Server — The default for macOS Server systems. No crash reports are shown to the user (though they are still logged). None — Disables the dialog prompt. Crash reports are neither displayed nor logged. The developer tool CrashReporterPrefs can be used to change modes, as can using the terminal command defaults write com.apple.CrashReporter DialogType [basic|developer|server]. In basic mode, if Crash Reporter notices an application has crashed twice in succession, it will offer to rename the application's preference file and try again (corrupted preference files being a common cause of crashes). When reporting a crash, the top text field of the window has the crash log, while the bottom field is for user comments. Users may also copy and paste the log into their e-mail client to send to a third-party application developer for the developer to use. DiskImageMounter DiskImageMounter is the utility that handles mounting disk volume images in Mac OS X, starting with version 10.3. DiskImageMounter works by either launching a daemon to handle the disk image or by contacting a running daemon and have it mount the disk. Like BOMArchiveHelper, DiskImageMounter has no GUI when double-clicked; doing so does nothing. The only GUI the program ever displays is a window with a progress bar and mount options (cancel or skip verification) or an error report if it could not mount the image. It is found in /System/Library/CoreServices/DiskImageMounter.app. Starting with version 10.7, Apple "removed double-click support for images using legacy metadata." DiskImageMounter will not be able to open .img (NDIF only), .smi (self mounting), .dc42 (Disk Copy 4.2), and .dart (DART) disk image formats that was previously supported in version 10.6 and earlier. DiskImageMounter supports a variety of disk image file types: Apple Disk Image (.dmg, com.apple.disk-image) UDIF disk images (.udif, com.apple.disk-image-udif); UDIF segment (.devs, .dmgpart, com.apple.disk-image-udif-segment) self mounting image (.smi, com.apple.disk-image-smi) DVD/CD-R master image (.toast, .dvdr, .cdr, com.apple.disk-image-cdr, com.roxio.disk-image-toast) disk image segment (dmgpart) raw disk image (OSTypes: devr, hdrv, DDim, com.apple.disk-image-raw) PC drive container (OSTypes: OPCD, com.apple.disk-image-pc) ISO image (.iso, public.iso-image) sparse disk image (.sparseimage, com.apple.disk-image-sparse, .sparsebundle) As of macOS 11.0, support for the following formats has been