There are two admin user accounts on my MacBook. I want to install different versions of a software program (OmniGraffle) on each user account. Is this possible?
Sure, just copy the application into the home directory of each user. I usually have an user specific Applications directory for each user, in their own directory. So you would have
You can also rename the application directory (add the version number), and make both versions available from the system Applications folder.