How to install?
Step 1: Download Rosetta Stone 3.4.5 Full version here.
Step 2: Launch Rosetta Stone Version 3.dmg
Step 3: After installing, go to Application, then right mouse on Rosetta Stone Version 3.app, choosing Show Package Contents. Then copy the mdm.dat into /Contents/Resources folder.
Step 4: Choose the language you need here, then all language.
You may want to use DiskImageMouter to deal with the .iso file on Mac.