Although support for macOS is still officially experimental, DiskDigger can run fairly well under older versions of macOS, thanks to the current state of Mono support for macOS. To get DiskDigger running, follow these steps:
$ sudo mono --arch=32 DiskDigger.exe
The "--arch=32" parameter is necessary because the Carbon driver for Windows Forms has not yet been ported to 64 bits.
Since the Mono implementation of Windows Forms on macOS is not yet completely mature, you may still see some graphical glitches or inconsistencies when running DiskDigger. These will hopefully be ironed out in future updates. Stay tuned!
MacOS Catalina no longer allows 32-bit applications of any kind to run. Since WinForms for Mono requires the 32-bit version of the Carbon driver, this means that DiskDigger cannot run on macOS Catalina at this time. Check back later for potential fixes or workarounds.