QuadToneRIP version 2.7.7 Release Notes The Mac OSX release is specifically for OSX El Capitan compatibility. The Windows release is specifically for Windows 10 compatibility. El Capitan prohibits installations in an area that was used by QTR so this update moves those files to a permitted area. It's recommended that you update QTR to 2.7.7 before updating your OSX to El Capitan. This cleans out the old locations while access is still permitted. If you don't QTR still will work just fine but if you Add Printer in System Preferences it will appear that 2.7.6 is still installed -- in fact this will point to new code but the 2.7.6 may be confusing. The Mac release supports Mac OS X 10.6 Snow Leopard through 10.11 El Capitan. Simply install this new version over existing versions.