If you are running Firefox on a Mac, you’ve more than likely came across the problem that it has no idea what to do with a .dmg file.
Ideally we’d want it to open the .dmg just like it does a .zip file and I’ve figured out how to do that.
Here is how to tell Firefox to mount a .dmg file on a Mac
1) Click here to go to Mozilla and click on the green Download Firefox button. This may sound odd, but it’s a must. This set of instructions will only work on this dmg for reasons that are probably hard to explain. Trust me here.
2) A window will pop up asking you what you want to do with this DMG. Click the ‘Choose…’ button.
3) Navigate to your-harddrive/system/library/CoreServices/ and choose DiskImageMounter
4) Click the ‘Do this automatically…’ check box to save the setting.
5) Hit OK. If you don’t actually want to download Firefox again, just cancel the download.
That’s it. All .dmg files should now open automatically.
If that doesn’t seem to work right, then go to Firefox -> Preferences -> Downloads and click on the ‘View & Edit Actions…’ button. Look for DMG, click on it, click ‘Change Action…’ and choose ‘Open them with this application’ and browse to DiskImageMounter again. This will clear up any confusion within Firefox but you must perform the steps above first or else you can’t even get DMG into the list.
To get Firefox to open .zip files with Apple’s BOMArchiveHelper instead of Stuffit go to Firefox -> Preferences -> Downloads and click on the ‘View & Edit Actions…’ button. Look for ZIP, click on it, click ‘Change Action…’ and choose ‘Open them with this application’ and browse to BOMArchiveHelper which is in the same CoreServices folder as DiskImageHelper.