How to run two versions simultaneously on a Mac?
How to run two versions simultaneously on a Mac? Installing multiple versions on Mac OS X is basically dragging the Firefox application out of the DMG file to the desktop and rename the folder. You can drag the renamed Firefox application folder to the Applications folder like you would normally install Firefox. You need to use the terminal to create a new profile for that version. Make sure that no profile is selected as the default to make the Profile Manager show when you start Firefox. You can check that in the profiles.ini file. http://kb.mozillazine.org/profiles.ini_file http://kb.mozillazine.org/Profile_Manager Originally from https://support.mozilla.org/en-US/questions/1149213