How to share your applications on Mac OSX with other users on same local iMac?

Question

i.e., Firefox web browser, OpenOffice, Parallels VM...

Answer 1

If the programs are installed to /applications they should be accessible to all users, though if they are installed to ~/applications they will only be accessible to your account. Copying them to /applications should fix your problem, though it would not hurt to either backup first, or be sure to copy, rather than cut.