Share Protected directory between sites

I have a series of sites organized by city. All of them share the database and framework, but is it possible to share views, models and controllers? All of the site specific data is stored in the database so all of the code is the same. Only the config file needs to be different.

Yes, just set the same basePath for all applications in config files.

Wow. I read right over that line in the config file. Thank you.